Police have arrested a man in connection with the theft of papers belonging to a candidate who stood against Labour's Peter Mandelson at Hartlepool in the General Election, it emerged yesterday.

John Booth, who unsuccessfully fought the seat as Genuine Labour - although that description of him was not registered - said he had received a letter from Cleveland Police saying they had "identified, traced and arrested the person who found your papers and who subsequently appropriated them".

The letter said: "The individual is now on police bail whilst the case papers are reviewed by the Crown Prosecution Service".

A police spokesman said later that the person arrested was male, but no further information was being made available.

Mr Booth said at the time that he visited a newsagent in Hartlepool to copy some documents and discovered, on his return to his office, that he had left one original document, part of a letter to the BBC, in the copying machine.

He returned to the shop immediately to find that the document had disappeared from the machine and that nobody had handed it in to the shop's owner or staff, he said.

He then notified the police.

In the 1980s, Mr Booth worked as a deputy to Mr Mandelson, who was then the Labour Party's Director of Communications