Finding: Police have announced that MI6 spy Gareth Williams probably locked himself in the holdall where he was found dead in August 2010 . Police today admitted that they are unable to explain the death of an MI6 spy whose body was found locked in a holdall bag. Gareth Williams' mysterious death has been the subject of fierce speculation since he was found dead in his Central London flat three years ago. Following a year-long investigation by Scotland Yard, officers today announced that they believe his death was accidental and that no one else was involved, although they concluded that it is impossible to reach a definite verdict on the case. The finding contravenes the verdict of a coroner who last year ruled that Mr Williams had 'probably' been killed by someone else. Scotland Yard detectives said that since it was possible for the codebreaker to climb in to the bag and lock it unaided, it is not necessary to posit any outside involvement. They added that there was no evidence of anyone else in his flat at the time of his death, and no sign that the home had undergone a 'deep clean' to avoid incriminating a third party. However, the review also found traces of DNA in the flat from 10 to 15 different people, none of whom they were able to identify. Deputy Assistant Commissioner Martin Hewitt said: 'With the conclusion of the investigation, the Metropolitan Police's position is that, on balance, it is a more probable conclusion that there was no other person present when Gareth died. 'But the reality is that for both hypotheses, there exist evidential contradictions and gaps in our understanding.' Although he said that Mr Williams' death was 'most probably' an accident, he admitted: 'No evidence has been identified to establish the full circumstances of Gareth's death beyond all reasonable doubt.' Mystery: The body of Gareth Williams lay undiscovered in a red holdall in the bath of his Pimlico flat for a week before security service bosses raised the alarm . However, the family of the . 31-year-old disagree with the verdict, and continue . to support the coroner's theory that he was unlawfully killed. They . said in a statement: 'We are naturally disappointed that it is still . not possible to state with certainty how Gareth died and the fact that . the circumstances of his death are still unknown adds to our grief. 'We . consider that on the basis of the facts known at present the coroner's . verdict accurately reflects the circumstances of Gareth's death.' Mr Hewitt admitted that the police and MI6 had failed to co-operate fully, but said it was 'beyond credibility' that his investigation had been deliberately deceived by anyone trying to hide the truth about Mr Williams' death. 'I do not believe that I have had the wool pulled over my eyes,' he said. 'I believe that what we are dealing with is a tragic unexplained death.' Reconstruction: A yoga expert tried to climb into a similar holdall in a video shown at Mr Williams' inquest . Home: The scene inside the spy's flat in Pimlico, Central London, where he was found dead . Following the inquest, police were given access to the codebreaker's personnel and vetting files, but found that there was 'no evidence to support the theory that Gareth's death was in any way related to his work'. Mr Hewitt went on: 'Three years of extensive investigative activity have developed a very clear profile of Gareth. He was, without doubt, a private person who was very close to his family and had few other close friends. 'That said, the universal view of colleagues was of a conscientious and decent man with a few well-known hobbies such as his cycling and climbing. There is no evidence of any animosity towards Gareth, and it has not been possible to identify anyone with a motive for causing him harm.' Mr Williams, who was found dead inside . the locked bag in the bath of his flat in Pimlico in August 2010, is . known to have had an interest in escapology. He once had to be rescued by his landlady after he apparently tied himself to his bed wearing only boxer shorts and was unable to free himself. Last image: Mr Williams pictured on CCTV at a Tube station shortly before his death . MI6 failed to raise the alarm about his disappearance for more than a week after he failed to turn up for work at the agency's headquarters in Vauxhall. His family said: 'We still remain . very disappointed over the failure of his employers at MI6 to take even . the most basic inquiries concerning Gareth's welfare when he failed to . attend for work on August 16 2010. 'We . believe that if proper steps had been taken in the same manner as any . reasonable employer would have undertaken, further information relating . to the cause of his death might have become apparent and not have been . lost due to the length of time before Gareth's body was found. 'This . lack of concern for Gareth's wellbeing remains an overriding feature of . our thoughts following the death of a dear son and brother.' Coroner Fiona Wilcox ruled in May last year . that the spy would not have been able to lock himself in the bag and was . therefore likely to have died at somebody else's hands. She . concluded: 'The cause of his death was unnatural and likely to have . been criminally mediated. I am therefore satisfied that on the balance . of probabilities that Gareth was killed unlawfully.' Bag: Mr Williams was found locked inside a red North Face holdall similar to this one . Family: Mr Williams' parents, Ellen and Ian, at the inquest into his death in April last year. They stand by a coroner's ruling that the brilliant codebreaker was probably killed unlawfully . But . within days of the verdict investigators claimed that it was in fact . possible for a skilled escapologist to climb in to the red North Face . holdall and lock it from the inside. Police launched a review of the case following the inquest, over concerns that some evidence had been handled improperly. The . investigation included interviews with 27 officials from both . MI6 and GCHQ, from where Mr Williams, who was originally from Anglesey, had been seconded. Police said that Dr Wilcox has accepted their findings, but decided that there is insufficient new evidence to justify re-opening the inquest. Theories: Many possible explanations for Mr Williams' death have previously been suggested but rejected by police . The Metropolitan Police's conclusion that the Gareth Williams' death was nothing more than a tragic accident could put to rest the various theories which have attached themselves to the case. It has long been suspected that Mr Williams could have been targeted by foreign agents because of his highly sensitive MI6 work. He was said to be a mathematical prodigy, sent by GCHQ to work at MI6 for a year thanks to his exceptional skills as a codebreaker. Another theory was that the Russian mafia assassinated him in a bid to stop him investigating money-laundering networks. Others suspected that his death might have been the result of a sex game gone wrong, after it was claimed that he had close links with London's drag and bondage scenes. A collection of women's designer clothes and shoes worth £15,000 was found in his closed, raising the possibility that he may have been a cross-dresser, although friends insisted that he had bought the clothes as gifts for others. Mr Williams' relatives have previously suggested that incriminating items were planted in his flat after his death to cast doubt on his character. Police issued e-fit images of a couple who were apparently seen visiting the spy shortly before he died, amidst suggestions they could hold the answer to the mystery. Today's finding that Mr Williams's death was probably accidental has failed to satisfy not only his family, but dozens of members of the public who took to Twitter to express scepticism about Scotland Yard's verdict. Many people continue to insist that it would have been impossible for the 31-year-old to lock himself inside the holdall without leaving any traces of DNA on the padlock. Despite the Metropolitan Police's conclusion that the death of Gareth Williams was probably an accident, a number of questions surrounding the mystery remain unanswered. Scotland Yard claims that no one else was present in the spy's flat when he died, but investigators were unable to identify the DNA of 10 to 15 people which was found at the property. By contrast, there were no traces of Mr Williams' own DNA on the padlock of the bag he was found in, nor were his palm prints found on the bathtub which held the bag. The central heating was turned on in the Central London flat where the spy was living, even though it was August, a mystery not explained by the police investigation. Moreover, it remains unclear why MI6 failed to report Mr Williams missing for a week after he repeatedly failed to turn up to work, a failing for which his manager publicly apologised during his inquest. Attention initially focussed on a Mediterranean-looking couple believed to have visited the spy's home around the time of his death, but they have never been found or identified.
Gareth Williams found dead in his Central London flat in August 2010 .
31-year-old's death was ruled to be 'probably' foul play by a coroner .
But Scotland Yard announced that he seems to have locked himself in bag .
Police admitted that they could not reach a conclusion 'beyond doubt'
Family believe he was killed and refuse to accept result of investigation .
Finding: Police have announced that MI6 spy Gareth Williams probably locked himself in the holdall where he was found dead in August 2010 . Police today admitted that they are unable to explain the death of an MI6 spy whose body was found locked in a holdall bag. Gareth Williams' mysterious death has been the subject of fierce speculation since he was found dead in his Central London flat three years ago. Following a year-long investigation by Scotland Yard, officers today announced that they believe his death was accidental and that no one else was involved, although they concluded that it is impossible to reach a definite verdict on the case. The finding contravenes the verdict of a coroner who last year ruled that Mr Williams had 'probably' been killed by someone else. Scotland Yard detectives said that since it was possible for the codebreaker to climb in to the bag and lock it unaided, it is not necessary to posit any outside involvement. They added that there was no evidence of anyone else in his flat at the time of his death, and no sign that the home had undergone a 'deep clean' to avoid incriminating a third party. However, the review also found traces of DNA in the flat from 10 to 15 different people, none of whom they were able to identify. Deputy Assistant Commissioner Martin Hewitt said: 'With the conclusion of the investigation, the Metropolitan Police's position is that, on balance, it is a more probable conclusion that there was no other person present when Gareth died. 'But the reality is that for both hypotheses, there exist evidential contradictions and gaps in our understanding.' Although he said that Mr Williams' death was 'most probably' an accident, he admitted: 'No evidence has been identified to establish the full circumstances of Gareth's death beyond all reasonable doubt.' Mystery: The body of Gareth Williams lay undiscovered in a red holdall in the bath of his Pimlico flat for a week before security service bosses raised the alarm . However, the family of the . 31-year-old disagree with the verdict, and continue . to support the coroner's theory that he was unlawfully killed. They . said in a statement: 'We are naturally disappointed that it is still . not possible to state with certainty how Gareth died and the fact that . the circumstances of his death are still unknown adds to our grief. 'We . consider that on the basis of the facts known at present the coroner's . verdict accurately reflects the circumstances of Gareth's death.' Mr Hewitt admitted that the police and MI6 had failed to co-operate fully, but said it was 'beyond credibility' that his investigation had been deliberately deceived by anyone trying to hide the truth about Mr Williams' death. 'I do not believe that I have had the wool pulled over my eyes,' he said. 'I believe that what we are dealing with is a tragic unexplained death.' Reconstruction: A yoga expert tried to climb into a similar holdall in a video shown at Mr Williams' inquest . Home: The scene inside the spy's flat in Pimlico, Central London, where he was found dead . Following the inquest, police were given access to the codebreaker's personnel and vetting files, but found that there was 'no evidence to support the theory that Gareth's death was in any way related to his work'. Mr Hewitt went on: 'Three years of extensive investigative activity have developed a very clear profile of Gareth. He was, without doubt, a private person who was very close to his family and had few other close friends. 'That said, the universal view of colleagues was of a conscientious and decent man with a few well-known hobbies such as his cycling and climbing. There is no evidence of any animosity towards Gareth, and it has not been possible to identify anyone with a motive for causing him harm.' Mr Williams, who was found dead inside . the locked bag in the bath of his flat in Pimlico in August 2010, is . known to have had an interest in escapology. He once had to be rescued by his landlady after he apparently tied himself to his bed wearing only boxer shorts and was unable to free himself. Last image: Mr Williams pictured on CCTV at a Tube station shortly before his death . MI6 failed to raise the alarm about his disappearance for more than a week after he failed to turn up for work at the agency's headquarters in Vauxhall. His family said: 'We still remain . very disappointed over the failure of his employers at MI6 to take even . the most basic inquiries concerning Gareth's welfare when he failed to . attend for work on August 16 2010. 'We . believe that if proper steps had been taken in the same manner as any . reasonable employer would have undertaken, further information relating . to the cause of his death might have become apparent and not have been . lost due to the length of time before Gareth's body was found. 'This . lack of concern for Gareth's wellbeing remains an overriding feature of . our thoughts following the death of a dear son and brother.' Coroner Fiona Wilcox ruled in May last year . that the spy would not have been able to lock himself in the bag and was . therefore likely to have died at somebody else's hands. She . concluded: 'The cause of his death was unnatural and likely to have . been criminally mediated. I am therefore satisfied that on the balance . of probabilities that Gareth was killed unlawfully.' Bag: Mr Williams was found locked inside a red North Face holdall similar to this one . Family: Mr Williams' parents, Ellen and Ian, at the inquest into his death in April last year. They stand by a coroner's ruling that the brilliant codebreaker was probably killed unlawfully . But . within days of the verdict investigators claimed that it was in fact . possible for a skilled escapologist to climb in to the red North Face . holdall and lock it from the inside. Police launched a review of the case following the inquest, over concerns that some evidence had been handled improperly. The . investigation included interviews with 27 officials from both . MI6 and GCHQ, from where Mr Williams, who was originally from Anglesey, had been seconded. Police said that Dr Wilcox has accepted their findings, but decided that there is insufficient new evidence to justify re-opening the inquest. Theories: Many possible explanations for Mr Williams' death have previously been suggested but rejected by police . The Metropolitan Police's conclusion that the Gareth Williams' death was nothing more than a tragic accident could put to rest the various theories which have attached themselves to the case. It has long been suspected that Mr Williams could have been targeted by foreign agents because of his highly sensitive MI6 work. He was said to be a mathematical prodigy, sent by GCHQ to work at MI6 for a year thanks to his exceptional skills as a codebreaker. Another theory was that the Russian mafia assassinated him in a bid to stop him investigating money-laundering networks. Others suspected that his death might have been the result of a sex game gone wrong, after it was claimed that he had close links with London's drag and bondage scenes. A collection of women's designer clothes and shoes worth £15,000 was found in his closed, raising the possibility that he may have been a cross-dresser, although friends insisted that he had bought the clothes as gifts for others. Mr Williams' relatives have previously suggested that incriminating items were planted in his flat after his death to cast doubt on his character. Police issued e-fit images of a couple who were apparently seen visiting the spy shortly before he died, amidst suggestions they could hold the answer to the mystery. Today's finding that Mr Williams's death was probably accidental has failed to satisfy not only his family, but dozens of members of the public who took to Twitter to express scepticism about Scotland Yard's verdict. Many people continue to insist that it would have been impossible for the 31-year-old to lock himself inside the holdall without leaving any traces of DNA on the padlock. Despite the Metropolitan Police's conclusion that the death of Gareth Williams was probably an accident, a number of questions surrounding the mystery remain unanswered. Scotland Yard claims that no one else was present in the spy's flat when he died, but investigators were unable to identify the DNA of 10 to 15 people which was found at the property. By contrast, there were no traces of Mr Williams' own DNA on the padlock of the bag he was found in, nor were his palm prints found on the bathtub which held the bag. The central heating was turned on in the Central London flat where the spy was living, even though it was August, a mystery not explained by the police investigation. Moreover, it remains unclear why MI6 failed to report Mr Williams missing for a week after he repeatedly failed to turn up to work, a failing for which his manager publicly apologised during his inquest. Attention initially focussed on a Mediterranean-looking couple believed to have visited the spy's home around the time of his death, but they have never been found or identified.
Williams probably locked himself in the holdall where he was found dead in August 2010 . Police locked in a holdall bag. Gareth Williams' year-long investigation by Scotland Yard, officers today announced that they believe his Gareth's death beyond all reasonable doubt.' Gareth's death.' Mr Hewitt admitted that the inside the spy's flat in Pimlico, Central London, unnatural and likely to have . been criminally balance . of probabilities that Gareth was killed