A teenager was arrested and cautioned today for posting a bogus message on Facebook which claimed to be from missing chef Claudia Lawrence.
North Yorkshire Police said an 18-year-old man from Didcot, Oxfordshire, was cautioned after he admitted making a malicious communication and wasting police time.
The message appeared on the "Claudia Lawrence Investigation" Facebook page in November 2009. Miss Lawrence was last seen on March 18, 2009, after leaving work at York University.
The bogus message read: "Hi everyone just let you be aware that I am ok and I am safe and sound. Speak to you all soon. Claudia. xxx."
A police spokesman said the teenager was cautioned for both offences and released. Police said the matter had now been dealt with.
Detective Superintendent Ray Galloway, who is leading the investigation into the suspected murder of Miss Lawrence, said: "The posting of this message on Facebook, claiming to be Claudia Lawrence, caused significant anxiety and distress to Claudia's family and also diverted valuable police resources to pursue a line of inquiry that had no value.
"The arrest demonstrates our determination to pursue anybody that undertakes such malicious and irresponsible behaviour.
"The investigation into the suspected murder of Claudia Lawrence continues and will do so whilst there are positive lines of inquiry to pursue."
The investigation team is still trying to establish Miss Lawrence's exact movements from 8.30pm on Wednesday March 18 when she was last in contact with her parents via telephone from her home.
The 35-year-old was due to walk the three miles to work the following day for a shift beginning at 6am. But she never turned up for work on that day.
Despite the intensive police search effort in and around the Heworth and York University area, and detailed inquiries elsewhere, her disappearance remains unexplained and is being treated as suspected murder.
Her mobile phone - a Silver Samsung D900 - and blue Karrimor rucksack in which she carried her chef's whites, have still yet to be located.
Her father, Peter Lawrence, 63, from North Yorkshire, has mounted a high-profile media campaign over the last 11 months in a bid to find out what has happened to his daughter.