Daily Post : Claims building in which Anglesey MI6 spy lived in was broken into

Claims building in which Anglesey MI6 spy lived in was broken into

by Dan Beavan, DPW West | February 20, 2012

SECURITY concerns had been raised in the months before the body of a spy was found in a holdall it has been claimed.

The body of 31-year-old GCHQ code-breaker Gareth Williams, from Valley, Anglesey, was discovered in his London flat in August 2010.

He had been padlocked inside a holdall that was left in an empty bath.

His death appeared a baffling mystery to Met Police.

But according to a leading Sunday newspaper, a source close to Mr Williams has come forward claiming the Pimlico building, where the spy lived in London, was broken into several months before his death, which has apparently not been revealed by the authorities.

According to the source Mr Williams had told him a female occupant on the ground floor flat had asked the spy to swap apartments after hers was broken into.

The property was used by MI6 to house its agents.

A major investigation by the Met Police was launched but has so far failed to establish what led to his death.

Westminster Coroner’s Court has said a pre-inquest review will take place on March 29, with a full inquest to follow three weeks later.

The inquest is expected to last four days.

Daily Post : Inquest into death of Anglesey MI6 spy Gareth Williams to take place in April

Inquest into death of Anglesey MI6 spy Gareth Williams to take place in April

by Dan Beavan | DPW West | January 31, 2012

THE inquest into the death of MI6 spy Gareth Williams will take place in April.

Codebreaker Mr Williams, 31, from Valley, Anglesey, was found dead locked in a sports bag at his central London flat in August 2010.

A major investigation by the Metropolitan Police has failed to establish what led to his death.

Now Westminster Coroner’s Court has said that a pre-inquest review will take place on March 29, with a full inquest to follow three weeks later.

The inquest is expected to last four days.

It will be held by Westminster coroner Dr Fiona Wilcox at Horseferry Road Coroner’s Court in London.

The review will establish who will give evidence and also in what form, with some evidence given “in camera” to protect the identities of Mr Williams’ former colleagues at MI6.

Former Ysgol Uwchradd Bodedern pupil Mr Williams was a gifted mathematician who attained a first class degree in maths aged just 17.

He began work at the Government Communications HQ in Cheltenham before being seconded to MI6 for a year.

His death attracted worldwide attention and huge speculation over how he died and if it was linked to his work as a spy with MI6 or his private life.

Daily Post : MI6 spy death probe continues

MI6 spy death probe continues

by Dan Beavan, DPW West | August 24, 2011

POLICE are still investigating the death of MI6 spy Gareth Williams – a year after his body was found locked in a sports bag in his flat.

Codebreaker Mr Williams, 31, from Valley, Anglesey, was discovered at his central London flat 12 months ago.

Mystery still surrounds the death with detectives saying his private life remains the main focus of the investigation, which they say is active.

Twelve months on Mr Williams' death remains suspicious and unexplained.

A date for his inquest has still not been set although sources say it will take place before Christmas and last several weeks.

Former Ysgol Uwchradd Bodedern pupil Mr Williams was a gifted mathematician who attained a first class degree in maths aged just 17.

He began work at the Government Communications Headquarters in Cheltenham before being seconded to MI6 for a year.

Daily Post Wales : 40 spies will give evidence at Gareth Williams inquest

40 spies will give evidence at Gareth Williams inquest

by Owen R Hughes, DPW West | February 16, 2011

UP to 40 spies could give evidence anonymously at the inquest into the mysterious death of MI6 agent Gareth Williams, a coroner was told yesterday.

Coroner Paul Knapman adjourned an inquiry into the 31-year-old’s death as Scotland Yard detectives wait for the results of a fresh round of forensic tests.

Counter-terrorism officers have interviewed “in the region of 40” of the expert codebreaker’s colleagues at MI6 and GCHQ, Westminster Coroner’s Court heard.

They have been passing on their findings to a team of investigators from the force’s Homicide and Serious Crime Command who are responsible for the inquiry.

The inquest heard that some or all of them could give evidence about Mr Williams, whose naked and decomposing body was found in a sports bag in the bath of his Pimlico flat last August.

Detective Chief Inspector Jackie Sebire admitted the likelihood of tracing a Mediterranean couple seen at Mr Williams’s home weeks before his death is diminishing.

She said it is “very unusual” for two teams of officers to be working on a suspicious death inquiry, but said the victim’s secretive occupation was the reason.

Speaking about forensic tests, she added: “We have done a phased submission of tests to the laboratory.

“We are still waiting for some outstanding tests that went out before Christmas.”

After a 10-minute hearing, Dr Knapman adjourned the inquest until Thursday March 31, but said it is not known whether it will go ahead then.

Dr Knapman said he had read a report summarising the forensic tests written by a police expert but added “it is a matter of some regret'” that the inquest cannot go ahead.

He said the Mediterranean couple have not come forward, there are no new clues and it appears to be “less and less likely that something will happen”.

The coroner added: “The fact you must face is that in six months or so they have not come forward, this couple, have they?”

Mrs Sebire replied: “That is correct, sir.” The senior detective added that a “raft” of forensic tests have taken place and she is still waiting for the results of some submitted six months ago and more recently.

Mrs Sebire said her team is dealing with the dead man’s private life, forensic tests and other inquiries while counter-terrorism officers are responsible for liaising with spy agencies.

She said she has regular meetings with her counterpart, passes instructions to him on who should be interviewed and could arrange to see a potential witness if necessary.

Dr Knapman said Mr Williams’ family expect a “thorough inquest” and was told they have “no problem whatsoever” with his colleagues being granted anonymity.

The pre-inquest hearing was told they were invited to attend yesterday but did not come.

They have appointed a solicitor to represent them.

Mr Williams, of Anglesey, was found in a large North Face holdall, sealed by a padlock, at his top-floor flat in Alderney Street on August 23.

The mysterious discovery sparked a painstaking Scotland Yard investigation, worldwide media frenzy, and several outlandish conspiracy theories.

A battery of post-mortem tests have so far failed to determine how he died and police found it would have been impossible for him to have locked himself inside.

No evidence of drugs, alcohol or poisons have been found but police said anyone zipped inside the bag would have quickly found the temperature unbearable and suffocated within 30 minutes.

Investigators believe the fitness and fashion enthusiast had gone to drag cabaret shows, had £15,000-worth of unworn women’s designer clothing in a wardrobe, and had visited bondage websites.

Police have released e-fit images of a young, casually-dressed Mediterranean couple who a neighbour buzzed through the communal doors of Mr Williams’s block in June or July.

Mr Williams was a mathematics prodigy who worked as a cipher and codes expert for GCHQ, the Government listening station, but had been on secondment to MI6.

Daily Post : Funeral of Anglesey MI6 code-breaker Gareth Williams

Funeral of Anglesey MI6 code-breaker Gareth Williams

by Owen R Hughes, Daily Post | September 25, 2010

TRIBUTES were paid to MI6 code-breaker Gareth Williams as he was laid to rest on Anglesey.

More than 150 family, friends and colleagues including MI6 head Sir John Sawers silently entered Bethel Chapel in Holyhead to pay their final respects.

The 31-year-old spy’s body was discovered trapped in a padlocked North Face holdall placed in the bath of his flat in Pimlico, London in August.

Mystery surrounds the death of the maths genius from Valley and police continue to investigate.

Yesterday his tearful relatives clutched each other for support as they followed his wreath and tribute covered coffin into the Baptist Chapel led by his dad Ian, mum Ellen, and sister Ceri.

Ceri’s husband Chris Subbe paid tribute to Gareth inside the chapel, describing him as a “source of joy” for his family.

He went on to talk about meeting Gareth with Ceri at the Ritz Hotel in June, where they spent the afternoon laughing and joking.

He said: “The world was ours for the taking, yet here I am three months later, to the day, trying to describe your rich life with my poor words.”

He added that Gareth had always provided subtle and thoughtful conversation.

“He was unbelievably gifted but remained so modest and humble, he was a source of joy to his family,” he added.

The service was led by Rev John Rice Rowlands and a second tribute was also read out by Gareth’s former headteacher at Ysgol Gynradd Morswyn, Islwyn Williams.

He remembered the former pupil’s brilliance for maths which saw him attain GCSE at the age of 10.

Mourners sang Bread of Heaven and Craig yr Oesoedd, which was written by Samuel Jonathan Griffith (Morswyn), whom Gareth’s former primary school was named after.

After leaving the chapel his body was taken for burial at Ynys Wen Cemetery, Valley.

Outside the chapel MI6 head Sir John added his own tribute to Gareth.

He said: “My deepest sympathies go to the family. Gareth was a hugely talented person and he was very modest and generous as well. He did really valuable work with us in the cause of national security.”

Mr Williams worked as a communications officer at GCHQ in Cheltenham, but had been living in London after a secondment to the secret intelligence service.

He was due to return to Cheltenham a week after his body was found, after being in London for a year.

The Metropolitan Police have described the inquiry into his death as “complex”.

Fitness mad Gareth had excelled at school and graduated from Bangor University with a First Class mathematics degree at the age of 19.

Donations in his memory received at the funeral were given to Llanberis, Aberglaslyn and Ogwen Mountain rescue.

Daily Post : Funeral for MI6 code breaker from Anglesey

Funeral for MI6 code breaker from Anglesey

by Dan Beavan, Daily Post | September 22, 2010

THE funeral of MI6 code breaker Gareth Williams, who was found dead in a sports bag in his London flat, will take place this Friday.

The 31-year-old’s unclothed body was found in a holdall in the bathroom of his Pimlico home by police on August 23.

Metropolitan Police are still investigating the "unexplained" death of Mr Williams, who came from Valley on Anglesey.

The family yesterday announced that his funeral will be held at Bethel Chapel in Holyhead on Friday at 1pm. He will then be laid to rest at Ynys Wen Cemetery, Valley.

Mr Williams worked as a communication officer at GCHQ in Cheltenham, but had been living in London after a secondment to the secret intelligence service.

He was due to return to Cheltenham a week after his body was found, after being in London for a year.

The Metropolitan Police have described the inquiry into his death as "complex".

An inquest was opened at Westminster Coroner’s Court earlier this month. It revealed his body was found in a zipped and padlocked red North Face holdall, which was in an empty bath in the en-suite bathroom.

There had been no forced entry into his flat and no property was missing.

Earlier this month the investigating team released CCTV images of Mr Williams, captured on August 14 and 15 in London.

Tributes have been paid locally to the fitness mad MI6 worker who had excelled at school and graduated from Bangor University with a First Class mathematics degree at the age of 19.

Donations in his memory received at the funeral will be given to Llanberis, Aberglaslyn and Ogwen Mountain rescue.

Daily Post : CCTV images of murdered spy Gareth Williams released

CCTV images of murdered spy Gareth Williams released

by Eryl Crump, Daily Post | September 7, 2010

Images of the last known sightings of murdered MI6 spy Gareth Williams before his body was discovered padlocked in a holdall have been released.

The CCTV images have been released by police as part of an appeal for information into the death of the 30-year-old from Valley, Anglesey.

They show Mr Williams out and about in London on the weekend of August 14/15. His body was found in a bag in the bath of his central London flat nine days later.

The first footage shows him entering Holland Park tube station in west London at about 3pm on August 14. A second bit of film shows him on the following day shopping in west London around the Brompton Road area and going into Harrods.

Detective Chief Inspector Jacqueline Sebire, who is leading the inquiry, said Mr Williams had returned from a planned holiday in the United States on Wednesday August 11 and went shopping “on a number of occasions” in the West End and Knightsbridge.

On Sunday August 15, he went to a cash machine and then to Harrods before CCTV images show him in Hans Crescent, heading towards Sloane Street, at about 2.30pm

Ms Sebire said: “I would appeal to anyone who may have seen or had contact with Gareth between August 11 and 23 to come forward and speak with us. This remains a complex unexplained death inquiry.”

Detectives said they were also trying to trace two people seen near the code-breaker's flat.

Ms Sebire said officers want to identify a man and a woman, both of Mediterranean appearance and aged between 20 and 30, who were let into the communal entrance of Mr Williams’ flat in Pimlico late one evening in June or July.

His body was found by officers who broke in after Mr Williams failed to appear at work for several days.

Post mortem examinations found “no obvious cause of death” and initial indications from toxicology tests showed no trace of any alcohol or routine or recreational drugs. Testing for any other substance is ongoing.

Ms Sebire said there was no sign of any forced entry to his flat in Alderney Street, no signs of disturbance inside, and no property was believed to be missing.

“There is no suggestion the items within the flat were specifically posed,” she said.

Mr Williams was days from completing a one-year secondment to the headquarters of the Secret Intelligence Service, MI6, in London.

His horrified family have paid tribute to him describing him as a “generous, loving son, brother and friend”.

A keen cyclist, Mr Williams often visited his family, who live at Valley near Holyhead, and often took part in events organised by Holyhead Cycling Club and Clwb Rasio Mona.

His family have hit out at rumours suggesting he was involved in risky sexual practices, saying they had been “very distressing”.

In a statement they said: “His loss has devastated us and we would ask anyone with information to come forward and assist the police inquiry.”

Police urged anyone with information to contact the incident room on 0208 358 0200 or call Crimestoppers anonymously on 0800 555 111.

Daily Post : Anglesey spy Gareth Williams' body was padlocked in holdall

Anglesey spy Gareth Williams' body was padlocked in holdall

by Our Correspondent, Daily Post | September 2, 2010

THE decomposing body of code-breaker Gareth Williams was found padlocked shut in a holdall in a bath in his flat, an inquest heard yesterday.

The cause of death is yet to be established after Mr Williams, from Valley on Anglesey, was discovered in the Government flat on August 23, Westminster Coroner’s Court heard.

Police broke into the top floor flat in Alderney Street, Pimlico, central London, after Mr Williams failed to appear at work for several days.

Coroner Dr Paul Knapman revealed he was found in a bag which was “padlocked shut” and the corpse appeared to be in an “advanced state of decay”, a court spokeswoman said.

A post mortem examination carried out on August 25 failed to establish a cause of death and investigations are continuing. The inquest was adjourned to September 8.

Dr Knapman will be kept informed of how the investigation is progressing and consider when to release the body so a funeral can take place.

There were no members of his family in court. His parents, Ian and Ellen, who live in Valley, were in London last week to identify their son’s body. His younger sister Ceri, who lives in the Wrexham area, is believed to have joined them.

Mr Williams, 30, a former pupil at Ysgol Morswyn, Holyhead, and Ysgol Uwchradd Bodedern, was last seen alive eight days before his corpse was discovered.

Police have not said whether the sighting was made on CCTV or came from another source.

The investigation is being led by the Met’s Homicide Command with the security-vetted Counter Terror Command (SO15) also playing a lesser role in proceedings.

Officers are still trying to determine if he was asphyxiated, poisoned or if drugs or alcohol were present in his system. A pathologist found Mr Williams was not stabbed or shot and there were no obvious signs of strangulation.

Mr Williams was a code-breaker at Government Communications Headquarters (GCHQ) in Cheltenham.

He was days from completing a one-year secondment to the headquarters of the Secret Intelligence Service, MI6, in Vauxhall, London.

Daily Post : Anglesey code-breaker was 'padlocked' into a holdall

Anglesey code-breaker was 'padlocked' into a holdall

September 1, 2010

THE decomposing body of Anglesey code-breaker Gareth Williams was found padlocked shut in a holdall in a bath in his flat, an inquest heard today.

The cause of death is yet to be established after he was discovered in the Government flat on August 23, Westminster Coroner’s Court heard.

Police broke into the top floor flat in Alderney Street, Pimlico, central London, after Mr Williams failed to appear at work for several days.

Coroner Dr Paul Knapman revealed he was found in a bag which was "padlocked shut" and the corpse appeared to be in an "advanced state of decay", a court spokeswoman said.

A post mortem examination carried out on August 25 failed to establish a cause of death and investigations are continuing, the court heard.

The inquest was adjourned to September 8.

Dr Knapman will be kept informed of how the investigation is progressing and consider when to release the body so a funeral can take place, the court spokeswoman said.

There were no members of his family in court.

Mr Williams, 30, was last seen alive eight days before his corpse was discovered.

Police have not said whether the sighting was made on CCTV or came from another source.

The investigation is being led by the Met’s Homicide Command with the security-vetted Counter Terror Command (SO15) also playing a lesser role in proceedings.

Officers are still trying to determine if he was asphyxiated, poisoned or if drugs or alcohol were present in his system.

A pathologist found Mr Williams was not stabbed or shot and there were no obvious signs of strangulation.

Mr Williams was days from completing a one-year secondment to the headquarters of the Secret Intelligence Service, MI6, in Vauxhall, London.

Daily Post : Murdered Anglesey spy was a 'generous and loving' say family

Murdered Anglesey spy was a 'generous and loving' say family

by Our Correspondent, Daily Post | August 28, 2010

THE North Wales family of murdered British spy Gareth Williams last night paid tribute to a “generous, loving son, brother, and friend” as police continued to investigate the death of the GCHQ codes expert.

It came as Scotland Yard detectives revealed the 30-year-old was last seen alive in the capital on Sunday August 15 eight days before his decomposing body was found at his London home.

His relatives, who live in Valley, Anglesey, said in a statement: “Gareth was a generous, loving son, brother, and friend, and he was a very private person.

“He was a great athlete, and loved cycling and music.

“His loss has devastated us and we would ask that anyone with information to come forward and assist the police inquiry.”

The mathematics genius, who was on secondment to MI6, was found dead in a sports holdall in the bath of his Government flat on Monday.

A Scotland Yard spokesman said: “We can confirm that Mr Williams was in London from Wednesday August 11, and what officers believe is the last confirmed sighting of him still alive in London was on Sunday August 15.”

Investigators have begun picking through his private life amid claims linking him to a male escort and suggestions that bondage equipment had been found at his home.

In the statement released by police, Mr Williams’ family said the “speculation” had been “very distressing”.

Sources close to the investigation have rejected the claims.

Relative William Hughes, 62, a councillor on Anglesey, insisted there was no evidence the allegations are correct.

Mr Hughes, a cousin of Mr Williams’ mother, Ellen, said: “I have spoken to Gareth’s parents and they are not doing well at all.

“They are in a state of shock and struggling to come to terms with what has happened.

“They have seen what has been in the papers and they are very, very upset about these untruths. I don’t see any evidence of it.

“It never crossed my mind that Gareth was that sort of person. He left home at a young age and what happened in his private life was his business.

“It is heartbreaking that he has died so young and his family have enough on their plate without having to read these stories.”

Mr Hughes said it was possible the Government, or another agency, might be attempting to discredit Mr Williams.

Police turned their focus to Mr Williams’ private life after colleagues discovered his body and raised the alarm.

He was days from completing a one-year secondment to the headquarters of the Secret Intelligence Service, MI6, in Vauxhall, London.

He was due to return to a rented flat in Cheltenham where Government Communications Headquarters, GCHQ, is based.

It is understood Mr Williams also worked for the United States National Security Agency and made regular trips to Washington DC and Fort Meade, near Baltimore.

The mystery over his final hours deepened after a post-mortem examination failed to identify a cause of death.

A pathologist found Mr Williams was not stabbed or shot and there were no obvious signs of strangulation.

Police have refused to categorise the death as a murder, despite the bizarre circumstances and say he may have died innocently.

Officers believe Mr Williams’ body could have lain undiscovered for many days and are examining his mobile phone and financial records.

Daily Post : Cyclists recall talents of murdered Holyhead spy Gareth Williams

Cyclists recall talents of murdered Holyhead spy Gareth Williams

by Deborah James, Daily Post | August 27, 2010

FELLOW cyclists paid tribute to codebreaker Gareth Williams for his skills on two wheels.

Mr Williams, 30, was a talented rider who regularly took part in road races and time trials. He was a former member of Holyhead Cycling Club and belonged to Cheltenham and County Cycling Club.

Records show he took part in cycling races in Snowdonia last September, and on Anglesey in September and on Valentine’s Day this year.

Speaking of their shock at learning of his suspicious death, friends from the cycling community described him as a “maths genius” who came across as “a very nice, friendly and quiet chap”.

Keith Thompson, of Holyhead Cycling Club, said he’d known Mr Williams since he joined the club aged of 17. He had won a trophy for being the Anglesey club’s junior best all rounder in 1996 and was named senior best all rounder from 1997 to 2000.

“I heard the news in a text message and it was a shock,” said Mr Thompson. “We are a small club, only 20 members, and all of us knew Gareth. We are totally devastated. He was a really lovely young man.

“Of course, once he moved to Cheltenham he joined the club there and we didn’t see much of him. I last saw him on our Boxing Day meeting last year. He was his usual self. It’s true that he was very quiet. He wasn’t a great conversationalist.

“We were club mates but Gareth wasn’t the sort to go to the pub after a race so he didn’t have any close friends in the group. I never spoke to him about his job or his private life. Nobody did.

“It was his cycling that we knew about. He was known for being very good on hill races. He was also a good runner, his whole family is very sporty. His father was a member of this club and (sister) Ceri was an athlete.

“We’ll be getting in touch to offer our condolences when they are home. We have also cancelled a club event we had planned for tonight. Nobody feels up to it now.”

David Hughes, from Clwb Rasio Mona, said: “As neighbouring clubs, we used to come across each other all the time. Although I didn’t know him personally, he was known around the cycling scene as a lovely person. He was a fine sportsman.”

While studying an advanced maths course at Cambridge in 2000, he joined the university cycling club and became the team’s “star rider”. Friends who raced alongside him left messages on the VeloRiders internet forum. One wrote: “He was a maths genius... People sometimes thought he was dense because he spoke rather slowly and sometimes seemed distracted. How wrong can you get?

A fellow Cambridge student called Tim said: “He seemed a shy and quiet chap, but had a peculiarly memorable laugh and smile that are haunting me somewhat today.”

Daily Post : Murdered MI6 spy Gareth Williams was from Anglesey

Murdered MI6 spy Gareth Williams was from Anglesey

by Eryl Crump, Daily Post | August 26, 2010

AN MI6 worker, whose body was found in a holdall at his central London flat, was born and raised on Anglesey.

Gareth Williams, 30, was discovered in the bath of the property in Pimlico, a short distance from the Secret Intelligence Service's headquarters.

Scotland Yard detectives immediately launched a murder investigation.

His parents, Ian and Ellen, who live in Valley near Holyhead, returned from holiday on Tuesday and were taken by police from Manchester Airport to London to identify their son’s body. His younger sister Ceri, who lives in the Wrexham area, is believed to have joined them.

They were still in London last night and other family members were comforting Mr Williams’ elderly grandparents.

Mr Williams’ uncle, Anglesey councillor William Hughes of Trefor near Bodedern, said he had a phone call on Tuesday morning to say the body had been found.

He said: “It was an enormous shock. I have been to see his grandparents and they cannot believe what has happened. We are all devastated.”

A former pupil at Ysgol Morswyn, Holyhead and Ysgol Uwchradd Bodedern, Mr Williams later studied Maths at Cambridge University.

“He was very, very talented but very quiet with it and didn’t mix a lot. He was very fond of cycling and always had his bike with him when he visited the island,” he said.

A former schoolfriend at Ysgol Uwchradd Bodedern said: “He was a really decent honest person, he was such a nice lad, quiet and hard working.

“You knew he was going places. He stood out because at every level at school he was so far ahead of everyone else in the class.”

Last night it emerged Mr Williams’ body may have been undiscovered for up to a fortnight before his colleagues raised the alarm.

Police broke down the door after attempts by the Foreign Office to locate him failed.

Mr Williams, who was employed as a communications officer at the GCHQ “listening post” in Cheltenham, Gloucestershire, was on secondment to the MI6 Secret Intelligence Service.

He was due to return to Cheltenham next week after working in London for about a year.

Mr Hughes added: “We knew he worked for GCHQ.. He would never talk about his work and it felt rude to ask really.”

His Cheltenham landlady Jenny Elliott said he was preparing to return on September 3.

She described him as “a lovely guy, very friendly, very well-mannered”. She added: “He was often away. He went to America to work a lot and often combined it with holiday because he hated flying.”

Mr Williams’s London neighbours described him as “extremely friendly, athletic, with a strong Welsh accent.

A post-mortem examination carried out by a Home Office pathologist last night found he had not been stabbed as earlier thought. Further tests, including toxicological analysis of his blood for evidence of drugs and alcohol, will now take place.

Daily Post : MI6 worker from Holyhead found murdered in London flat

MI6 worker from Holyhead found murdered in London flat

By Our Correspondent, Daily Post | August 25, 2010

A British spy found murdered in his flat might have lain undiscovered for up to two weeks.

The man, named locally as Gareth Williams, was found stuffed in a large sports holdall in the bath of his central London home.

Mr Williams, aged in his 30s and believed to be from Holyhead, was employed as a communications officer at the GCHQ "listening post" in Cheltenham, Gloucestershire.

He was on secondment to the riverside headquarters of MI6, the Secret Intelligence Service, about half a mile from the flat.

Officers discovered Mr Williams after breaking into the flat on Monday afternoon when the alarm was raised by colleagues who had not seen him for "some time".

They found his decomposing body, as well as his mobile phone and several Sim cards, laid out nearby at the top-floor flat in Alderney Street, Pimlico.

A post-mortem examination was being carried out by a Home Office pathologist today to establish what led to his death.

Sources close to the inquiry said it is not clear how he died and played down speculation that the murder is linked to his secretive line of work.

One source said: "The suggestion there is terrorism or national security links to this case is pretty low down the list of probabilities."

Neighbours described Mr Williams as an "extremely friendly" and athletic man who enjoyed cycling and had a strong Welsh accent.

They said he had lived in London for about a year and was planning to return to Cheltenham, where he rented a flat.

A postwoman who called at the block on Wednesday said he often collected parcels at the communal front door.

Secretary Laura Houghton, 30, said: "His windows were always shut and curtains were often closed. I could never tell if anyone was in.

"It was strange that we never saw him come and go. I just assumed he worked away.

"The first I heard of anything happening was when the police knocked on my door and asked me if I had heard anything happening. I told them the walls were so thick that I couldn’t hear a thing.

"All they told me was that there had been a serious incident. I’m amazed it’s taken this long to all come out."

Eileen Booth, 73, who lives opposite, said detectives told her the murder might have taken place two weeks ago.

She said: "A few years ago, I would definitely have known who it was that had been killed. But nobody knows each other these days.

"Detectives came round and asked for our eye colour and height. They said this probably happened two weeks ago."

The scene of the murder is a two-storey flat on a prestigious street among a row of expensive five-storey Victorian townhouses.

Residents are mainly bankers and politicians, including former home secretaries Michael Howard and Lord Brittan.

The ownership of the building is hidden behind the private company New Rodina, registered in the British Virgin Islands.

The property was bought for £675,250 in 2000, remortgaged twice and the word rodina means "motherland" in Russian and Bulgarian.

Public documents revealed several current and former residents of the freehold block have links to London and Cheltenham.

One Frenchman who lived at the flat between 2005 and 2006 is an expert in global satellite positioning, radio communications and high sensitivity antennae.

Officials at Scotland Yard’s Counter Terrorism Command and domestic intelligence agency MI5 have been kept up to date about the police inquiry.

The murder inquiry is being led by officers from Scotland Yard’s Homicide and Serious Crime Command.

A spokesman said the body was yet to be formally identified and a post-mortem examination would take place later on Wednesday.

He said investigators were following up "several lines of inquiry" but declined to confirm the occupation of the dead man.

It is the first murder on British soil of someone linked to the secret services since the death of Alexander Litvinenko in 2006.

The former KGB agent died in hospital after drinking tea laced with radioactive polonium-210.

Bulgarian defector Georgi Markov was killed by an assassin who used an umbrella to fire a deadly ricin pellet into his leg as he walked across Waterloo Bridge in September 1978.

A Foreign Office spokesman said: "There is an ongoing police investigation.

"It is long-standing Government policy not to confirm or deny that any individual works for the intelligence agencies."

A GCHQ spokesman said: "There is an ongoing police investigation and it would not be appropriate for us to comment at all as this is ongoing.

"We have nothing to add. Our policy is not to comment on individual members of staff or whether they are staff."

Mr Williams, 31, joined the University of Cambridge in 2000 to undertake a postgraduate certificate in advanced studies in mathematics but dropped out.

A spokeswoman said he was a member of St Catharine’s College but left without completing the qualification the next year.

The course is described as "demanding" and normally only accepts students with first-class degrees in physics, mathematics or engineering.

William Hughes, a relative of Mr Williams, said he had no idea of the type of work the spy was engaged in at GCHQ.

He said: "He worked for GCHQ for many years. I knew he was working in London doing something.

"He would never talk about his work and it felt rude to ask really."

Mr Hughes said he had not yet spoken to the dead man’s parents.

He added: "Unfortunately they were away out of the country. They have arrived back in the country today, I haven’t spoken to them yet.

"It was terrible when I had the phone call yesterday morning, I just didn’t know what to believe really, I didn’t know what to believe."

He said Williams was "very, very talented", adding: "We don’t know what he was doing, we never spoke about it."