Police investigating the death of British code-breaker Gareth Williams today appealed for help to trace two people seen near his Government flat.
Scotland Yard 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, central London, late one evening in June or July.
His decomposing naked body was found padlocked shut in a holdall in a bath in the top floor flat by officers who broke in on August 23 after Mr Williams failed to appear at work for several days.
Today, officers released CCTV footage of him as they appealed for the public's help.
It showed the 30-year-old entering Holland Park Underground station at about 3pm on Saturday August 14.
Police said 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.
A force spokesman added 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," he said.
Mr Williams was days from completing a one-year secondment to the headquarters of the Secret Intelligence Service, MI6, in Vauxhall, London.
Police 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 areas.
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, near the Dolce and Gabbana store, at about 2.30pm
Police said Mr Williams, who was 5ft 7in and of muscular build with short hair, was wearing a red T-shirt, beige trousers and white trainers.
Detective Chief Inspector Jacqueline Sebire, who is leading the inquiry for the force's homicide and serious crime command, said: "I would appeal to anyone who may have seen, or had contact with Gareth in the period between 11th and 23rd August to come forward and speak with us.
"This remains a complex unexplained death inquiry."
In a statement shortly after his body was found, Mr Williams' family hit out at rumours that suggested the GCHQ codes expert was involved in risky sexual practices, saying they had been "very distressing".
In tribute to him, they said: "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 anyone with information to come forward and assist the police inquiry."
Police urged anyone with information to contact the incident room on 020 8358 0200 or Crimestoppers anonymously on 0800 555 111.Reuse content