Detectives have marked the 15th anniversary of the disappearance of university chef Claudia Lawrence with a plea for those with information to break their silence.

Ms Lawrence was reported missing after she failed to report for work at the University of York in March 2009.

Her disappearance has been treated as a murder inquiry by North Yorkshire Police almost from the start, and the case had become one of the best-known unsolved crimes of the last 20 years.

On Monday, Acting Assistant Chief Constable Wayne Fox insisted the inquiry was not closed.