A £5,000 reward is on offer for help in solving an eight-year-old murder case where a man was found tied to his bed after lying there for nine days.
Alan Holmes, 53, was discovered at his flat in Parkway, Camden, on 4 January 1996 and died in hospital a day later.
Police believe that in the early hours of Boxing Day morning intruders had forced him to hand over bank cards and then tied him fully dressed to a bed.
He was only able to give a confused account of events before he died.
Mr Holmes, a single man who worked as a garage hand at Kentish Town Police Station, was last seen on Christmas Day when he had dinner with friends in west London.
They took him home at about midnight.
It is thought one or more intruders got into his second-floor flat where they robbed him and tied him up and that they may have returned to the flat in the following days.
About £1,000 was withdrawn using his two bank cards while Mr Holmes remained tied up.
After he failed to report to work, officers from Kentish Town station went to the flat and found him face down on the bed, critically ill and severely injured from having his limbs tightly bound.
Immobilised and dehydrated
He was taken to University College Hospital and was able to speak to police before he died on 5 January.
A post mortem examination gave the cause of death as blood clotting through immobilisation and dehydration.
Five men were arrested in the first three months of 1996 but all were released without charge.
"We would appeal to anyone who, eight years on from this tragic Christmas murder, feels they can now come forward with any information they have about the person or persons responsible," said Detective Inspector Anthony McKeown.
Anyone with information is asked to call 020 8247 7911 or freephone Crimestoppers anonymously on 0800 555 111.