Following several calls and new information police believe he may now be in the Burnley or Preston areas.

BBC: John Cattermole

Derbyshire Police said they had not ruled out the possibility he may be at racing events.

BBC: Owen Brennan: Police continue search for missing trainer

Expert witnesses and police officers may be able to withstand the pressure of their performance being broadcast, he said, but "fearful or intimidated witnesses would refuse to attend court, which could impact seriously if not terminally on the successful prosecution of a case".

BBC: Televising trials: What can be learned from US?

"Diverting resources away from following up current leads to track down people based on convictions that may be decades old is a questionable strategy at a time when the police are already overstretched, " he added.

BBC: A DNA autoradiogram

Appearing alongside Toby Harris , the chair of the Metropolitan Police Authority and deputy London Mayor Nicky Gavron , Mr Livingstone showed that although he may not be a Number 10 favourite, he still commands support among the rank-and-file.

BBC: Livingstone out on the fringe