The disappearance of York University chef Claudia Lawrence is now being treated as suspected murder , North Yorkshire Police said . However detectives said they had not found any proof that the 35-year-old , who went missing on 18 March , was dead . Her father Peter Lawrence made a direct appeal to his daughter to contact him five weeks after she disappeared . His plea came at a news conference held shortly after a 10,000 reward was offered to help find Miss Lawrence . Crimestoppers said the sum they were offering was significantly higher than usual because of public interest in the case .