New information has been revealed surrounding the life of an MI6 code-breaker from Anglesey who was found dead in his flat.
Gareth Williams’ body was discovered naked in a padlocked holdall last August.
Detectives believe someone helped put him in there and want them to come forward.
Mr Williams from Holyhead had been on secondment to MI6 from GCHQ.
His body was found in his Pimlico flat after concerns were raised by colleagues.
No evidence of drugs, alcohol or poisons were found during a series of tests conducted by toxicologists and a post mortem has been unable to determine how Mr. Williams died.
Det Ch Insp Sebire revealed police have forensic evidence that other people were in the flat, whom they have not been able to trace.
E-fits of the couple have now been released.
She added that an expert, brought in to examine the red North Face holdall in which Mr Williams was found, concluded he could not have locked it.
The keys had been found inside the bag.
Tests found the temperature inside the bag would have risen to 30C within three minutes.
An expert on survivability in confined spaces from the National Policing Improvement Agency (NPIA) said he would have suffocated in 30 minutes.
Detectives also unveiled infomation about the GCHQ worker’s private life. Officers told the press that the 31-year-old had viewed adult websites and had also visited a drag show shortly before his death.
Mr. Williams also owned £15,000 worth of women’s designer clothing, detectives said.
Detective Ch Supt Hamish Campbell said police hope that revealing some details of Mr Williams’ private life may encourage people to come forward.
He said: “This is not intended to add salacious detail or tittle-tattle.
“We feel there is some small sub-group of the community or individuals who may know something about this matter and the nature of Gareth’s death.
“They are naturally embarrassing, hurtful and distressing for the family but they are aware of the matters we are raising.”
Mr Campbell added that investigators are sure someone else involved with the bondage or gay scene has “linked in” with Mr Williams but police “cannot find that trace”.
He said: “We are very sure that someone else was in that flat. We want to know the circumstances when you would leave somebody in that position, by accident or design.”
He added: “Maybe, by explaining to the public, someone will think: ‘I get it and I can explain.”‘