article: The chef from York, North Yorkshire, went missing on 18 March 2009 at the age of 35. It was recently revealed that four men held as part of the police investigation would not face charges. Speaking to BBC Look North, Joan Lawrence said: "I have no instinct whatsoever that she isn't alive". Her comments come on a legal milestone which states a person may be legally declared dead after being missing for seven years. The previously arrested men, who are all in their 50s and from the York area, were held last year as part of a review of the initial investigation into the case. North Yorkshire Police said up to 20 detectives and police staff had worked full-time on the review for more than two years at a cost of nearly Â£800,000. Officers believed the investigation had been compromised by the "reluctance of some, and refusal of others, to co-operate" with the force. Mrs Lawrence said she was constantly surrounded by "reminders" of her daughter, whatever she was doing. She said: "Sometimes I feel like I'm banging my head against a brick wall, but I get through every day. "There's somebody out there who knows something, but I have no instinct whatsoever that she isn't alive, I've had no cut-off feeling at all. "In my opinion she's being held somewhere against her will and I want people to imagine if it was their child, how would they feel?" Claudia Lawrence disappearance timeline About 100 police officers were dedicated to the investigation at its height, but the figure has since dropped. Martin Dales, a friend and spokesman for Miss Lawrence's father Peter, said: "It seems that we're all back to square one. "It's really quite depressing especially as someone is clearly withholding the information needed." A North Yorkshire Police spokesman said: "The investigation team will continue to thoroughly assess any new leads and information. "We remind those who we suspect are withholding key information about Claudia that we will not give up our quest to find the truth."
summary: Seven years on from the disappearance of Claudia Lawrence, her mother has said she thinks she is alive and "being held somewhere against her will".