THE father of missing chef Claudia Lawrence today said there was "no excuse" for covering up for someone who may have information about his daughter's disappearance.

Peter Lawrence said it was possible a member of the public was shielding someone who had vital information about the 35-year-old's disappearance.

Speaking at a press briefing in Malton, North Yorkshire, Mr Lawrence said: "There is no excuse for covering up for what is potentially a serious investigation. And it is not doing us any good either."

Mr Lawrence, 62, said he was disappointed that no-one had come forward to say he was the person depicted in a BBC Crimewatch reconstruction.

He added: "I'm expressing my disappointment. I'm sure the rest of the family feel the same on this particular issue.

"No-one has seen fit to come forward and say that any of these sightings were us and it was nothing to do with it at all, or someone else who knows who it was could have come forward."

Asked if someone could be shielding a witness, he added: "That's always a possibility.

"But this is unfortunately potentially a criminal investigation and whoever it is should come forward."

The detective leading the hunt for Miss Lawrence has urged men who had a relationship with her to come forward if they wanted their information to be handled in a "discreet, confidential and controlled" manner.

Detective Superintendent Ray Galloway said it was vital that men who had a relationship with Miss Lawrence in her adult life came forward to help with the investigation into her disappearance.

Miss Lawrence, who disappeared nearly 12 weeks ago in York, was involved in relationships of "complexity and mystery", and kept those relationships secret from friends and family.

Mr Lawrence said there was no rift with the detective but questioned the language he used in the Crimewatch appeal.

He added: "I obviously knew the theme Mr Galloway was going to come out with on Crimewatch and why he was doing it. I take issue with him on the use of the language he used on Crimewatch."

Miss Lawrence was last seen near her home in York on March 18, and did not arrive for a 6am shift at a University of York kitchen the following morning.

North Yorkshire Police have now classified their investigation into her disappearance as one of suspected murder.