Dr Yves Godard, who has gone missing with his wife and two children, was the prime suspect in the case because he resembled a photofit of the suspected murderer.

But Robert Baffert, public prosecutor for the town of Rennes, western France, said tests had shown the doctor's DNA was different to the murderer's.

No further leads

Caroline, from Launceston, Cornwall, was 13 when she was killed in a youth hostel while on a school trip to Pleine Fougeres, Brittany, on 18 July 1996.

Hundreds of DNA samples have been taken from men in the region and from UK tourists who were there at the time, but the police are no closer to identifying the murderer.

Dr Godard was last seen on 5 September boarding a sailboat with his family in Saint-Malo.