Even after a coroner's verdict, it remains a mystery: A naked spy found dead in a locked bag, lurid details of a kinky sex life and allegations that someone in Britain's spy agencies may have been involved in his death.
A British coroner ruled Wednesday that another person was likely involved in Gareth Williams' death _ a finding that puts more pressure police to uncover the cyberwarfare expert's killer and continue to investigate possibilities that include whether he could have died in a sex game gone awry or in a more sinister scenario that involved his counterterrorism work.
In Britain, coroners are asked to investigate unexplained deaths, and their findings can often carry weight as police investigations proceed.
Although Coroner Fiona Wilcox said it was unlikely that the death of Williams, 31, will ever be "satisfactorily explained," she said the spy was likely killed either by suffocation or poisoning in a "criminally meditated act." She also said it was possible that someone from one of Britain's spy agencies was involved.
Williams, described as an introverted math genius, worked for Britain's secret eavesdropping service GCHQ. But he was attached to the MI6 foreign spy agency when his remains were found in the bathtub at his London apartment on Aug. 16, 2010, just a few days after returning from a trip to the United States.
Forensic experts found some 20,000 thousand pounds ($32,000) worth of luxury women's clothing, shoes and wigs in his apartment. Police also discovered that he had visited bondage and sadomasochism websites, including some related to claustrophilia _ a desire for confinement in enclosed spaces.
William's landlord testified during the coroner's hearing that she once found him handcuffed to his bed. She said he had appeared embarrassed after asking for help.
Still, Wilcox said there was no immediate evidence of a sexual encounter gone wrong, of suicidal intent, or that Williams' death was linked to a supposed interest in bondage. She said, however, that tales about his sex life could have been fueled in an attempt to "manipulate the evidence."
In the past, spy recruits were often cautioned that their sex lives could make them vulnerable to blackmail.
The case has frustrated Scotland Yard detectives who have been investigating the case for 21 months now and say that the secrecy surrounding Williams' job has thwarted their efforts.
"Obviously a lot of information has come out through the course of this inquest which we have not been party to," lead detective Jackie Sebire said.
But Wilcox also criticized the police detectives.
Time and resources were wasted, she said, when forensic teams investigating a DNA sample taken from Williams's hand later turned out to belong to one of the forensic scientists. She also questioned the handling of William's iPhone, which contained deleted images of him naked in a pair of boots.
Detective Superintendent Michael Broster, who was the police liason with MI6, said he had seized it from the spy's workplace and kept it until the next day when he gave it to another officer.
"I find this is either not what occurred ... or it demonstrates disregard for the rules governing continuity of evidence," Wilcox said.
Wilcox also criticized officers who interviewed Williams' colleagues without taking any formal statements.
"I find that this did affect the quality of evidence that was heard before this court," she said.
Still, the coroner said she had seen no evidence to indicate his death was linked to his work.
When the case emerged, some had speculated that he could have been the target of Russian criminal gangs or an al-Qaida extremist. Other media reports had said there had been a break-in at the property where he lived _ a building sometimes used by MI6 to house its agents.
Wilcox said while there wasn't evidence to support a specific verdict of unlawful killing _ which would need a high burden of proof _ it was her opinion that the spy was probably unlawfully killed.
She said while it appeared unlikely, speculation that British intelligence agencies may have had a role in the death continued to be a "legitimate line of inquiry."
MI6 waited a week to investigate why Williams hadn't shown up for work _ a delay that made it difficult for Williams' family to identify his badly decomposed body.
John Sawers, the head of MI6, said in a statement following the corner's verdict that he apologized "unreservedly" to the Williams family for the spy agency's failure.
During the coroner's hearing, MI6 accepted that Williams disliked the agency's boozy culture of post-work drinking and tedious bureaucracy, and had requested to return to his job at GCHQ.
One MI6 officer claimed that Williams hadn't been reported as missing because colleagues assumed he was preparing for his return to the southern England headquarters of the eavesdropping service.
Wilcox said it appeared unlikely that Williams could have climbed inside the duffel bag and locked it himself. Two different specialists attempted to recreate the feat without success. Williams was discovered in the fetal position inside the bag with two keys to the bag's padlock underneath his buttocks.
Pathologists told the inquest that poisoning or asphyxiation may have killed Williams, but said his cadaver was too badly decomposed to be certain.
Williams' family, who have been left distraught by parts of the inquest, did not speak outside court but offered a statement.
The family, from Wales, described Williams as a "special and adored son and brother" and said they "cannot describe the depth of the sorrow his absence leaves in our lives."
The police investigating is ongoing.
David Stringer contributed to this report.