A policeman arrived at the gates of Lewes prison with a prisoner to find he had forgotten the keys to his handcuffs.

Detective Constable Dave Field radioed the operator for help but asked if his oversight could be kept a secret.

A force insider said: "What a mistake. Word got round the whole force in seconds and produced an avalanche of ridicule on the force computer."

Brighton CID, where Mr Field is based, wrote on the computer log his secret would be safe provided he picked up doughnuts for colleagues on his way back.

Another station commented: "We want jam and chocolate ones."

One contributor said the entire Hastings-Bexhill division had been tannoyed with the story.

Gatwick-based Special Branch entered that the blunder was being circulated nationwide and Haywards Heath said Home Secretary David Blunkett had been informed.

Chichester-based Western division, Hove police, Uckfield and Crowborough stations, lost property departments and even traffic wardens promised to keep the secret.

Worthing custody officers said there was a job waiting for Mr Field in their prisoner cell block.

The insider said: "One contributor said he expected Mr Field's prisoner was singing Please Release Me while he was waiting. Another said he'd informed Interpol, MI5 and the Lewes branch of the Townswomen's Guild."

Mr Field, 32, said: "It was embarrassing and I've been suffering ever since it happened."

His boss, Detective Inspector Paul Fullwood, said: "He's a fine detective but I'm afraid he's in for some more stick.

"We've just had word a briefcase has been found in a car used on an inquiry. Guess who it belongs to?"