The mother of missing chef Claudia Lawrence said she has a gut instinct her daughter is abroad.
In her first full interview, Joan Lawrence also said she thinks the search for the 35-year-old needs some "new input" from the public.
Miss Lawrence was last seen near her home on Heworth Road, York, on March 18 and failed to arrive for a 6am shift at work at the University of York's Goodricke College the following day.
Since then, a huge police operation has failed to find any trace of her.
In a video interview for the Scarborough Evening News website, her mother said: "I don't think she's in the country. I think she's abroad. I don't know for certain. I have a gut instinct."
Mrs Lawrence, who lives in Norton, North Yorkshire, said she is concerned about the lack of new leads being generated by the public despite the "fantastic" help people have given so far.
"I don't think hardly anybody's come forward, really - nothing definite," she said. "I sometimes feel we're going down the wrong track. I think there's got to be new input."
But Mrs Lawrence said she had received hundreds of cards and letters from concerned members of the public.
She is divorced from Miss Lawrence's father, Peter, who has been leading the campaign to keep his daughter's plight in the public eye over the past two months. But whereas Mr Lawrence has been making weekly appeals for help, his ex-wife has been less willing to face the cameras.
North Yorkshire Police have now formally classified their investigation as one of suspected murder and the case will be featured on BBC1's Crimewatch programme again on June 2, after reconstructions were filmed in York last week.
