Police issue CCTV footage of dead MI6 worker

Gareth Williams pictured at tube station nine days before body was found, as police seek man and woman seen at flats

Police investigating the unexplained death of the MI6 officer Gareth Williams, whose decomposing body was found padlocked in a holdall in his bath, today released CCTV footage of him at a tube station last month.

Scotland Yard want to identify a man and a woman, aged between 20 and 30, who were let in to the communal entrance of his flat in Pimlico, central London, late one evening in June or July.

The CCTV images show Williams, wearing a red T-shirt, entering Holland Park station at 3pm on Saturday 14 August.

Police also released details of Williams's movements after he returned from a holiday in the US the previous Wednesday. He went shopping "on a number of occasions" in the West End and Knightsbridge areas, including in Harrods on Sunday 15 August. At about 2.30pm he was filmed in Hans Crescent, heading towards Sloane Street.

A police spokesman said that no drugs or indications of drug or alcohol use were recovered from the flat in Pimlico. There was no sign of any forced entry, no signs of disturbance inside and no property was believed to be missing.

Williams, a codebreaker on secondment from GCHQ Cheltenham, was discovered on Monday 23 August, eight days after he had last been seen. An inquest heard that his body was in "an advanced state of decay".

A postmortem examination established no obvious cause of death and police have denied a number of speculative reports about what was found in the flat.

Detective Chief Inspector Jacqueline Sebire, who is leading the inquiry, said: "This remains a complex unexplained death inquiry. I would appeal to anyone who may have seen or had contact with Gareth in the period between 11 and 23 August to come forward."