It is believed that Alan Holmes, a police civilian worker, was left bound and helpless for 10 days before officers forced their way into his home and found him seriously ill. He died the next day in hospital.
Mr Holmes, 53, a garage hand at Kentish Town police station, in north London, had dinner on Christmas Day with friends in west London, and was last seen when they dropped him off at his flat in Camden Town, north London, at about midnight, Scotland Yard said.
During the night Mr Holmes, a single man who lived alone, was dozing fully clothed in the second-floor flat when a burglar disturbed him, police believe. It is thought he was forced to hand over two bank cards.
At some stage Mr Holmes was kicked to make him divulge the cards' pin numbers. The suspect or suspects then tied him, face down, to a bed at the rear of the flat, and left.
Mr Holmes failed to report for work on 2 January and the next day officers from Kentish Town went to the flat, knocked and called through the letter box. There was no reply.
When Mr Holmes again failed to arrive for work on 4 January, officers returned to the flat, forced their way in and found him tied hand and foot, face down on the bed. He was seriously ill and had suffered injuries caused by having his limbs tightly tied. He was taken to University College hospital, where he died the next day. He was able to speak to police, but because of his condition was able to pass on only a certain amount of information.
A post-mortem examination was carried out and official information on the cause of death is awaited. "It is believed he died from blood clotting as a result of immobilisation and dehydration," a Scotland Yard spokesman said.
Police kept a news blackout on the case while an operation was mounted to catch the suspect or suspects, but it failed.
The stolen NatWest Servicetill and NatWest Access cards, both with Mr Holmes's name on, were used on a regular basis while he remained tied up in his flat. A total of about pounds 1,000 was taken from the two accounts.
Detective Chief Inspector John Yates, leading the inquiry, said: "We are looking for a man believed to be in his early twenties. He may be the athletic type, someone who lives on his wits and probably has an unsettled way of life, but is not necessarily a vagrant.
"He may frequent areas such as South Bank and Aldwych; we know the cards were used in those two places."
Chief Superintendent Linda Newham, the divisional commander at Kentish Town police station said: "Alan was a valued member of staff. He was a character with a good sense of humour. He is sadly missed at Kentish Town police station."Reuse content