Video: Four years on, the anguish of Claudia Lawrence’s father

Peter Lawrence admitted that it had been a “traumatic experience” to relive the ordeal of his daughter’s disappearance as part of the research for the book, which is called Gone and is published today.

He returned yesterday to York University’s Roger Kirk Centre, where Miss Lawrence worked as a chef before she went missing in March 2009, for the book’s official launch.

Mr Lawrence, 66, a solicitor from York, said: “It has been a painful experience to relive what has happened for the book. It has been very raw at times, but I wanted it to be written. To be back at the university has brought back a lot of painful memories. We were here just after Claudia went missing to put up posters appealing for information. That does seem like only yesterday, but it also feels like an eternity ago.”

Mr Lawrence has been spearheading a campaign to bring in legislation to aid the families of relatives who have vanished, and has been supported by the Missing People charity. The author of the book, Neil Root, has agreed to donate 35 per cent of his royalties to the charity.

New laws to introduce a certificate of presumed death in a bid to cut the red tape facing families of missing people is expected to be introduced by this summer. But Mr Lawrence has maintained the proposed overhaul does not go far enough to end the legal problems faced by distraught relatives. He wants to see new guardianship laws introduced to give families the chance to apply for power of attorney to deal with the legal affairs of missing relatives - and thereby streamline the legal system even further.

Miss Lawrence was aged 35 when she was last seen on March 18, 2009, near her home in the Heworth district of York. She never turned up to work at the university the following day.

North Yorkshire Police launched its biggest inquiry of recent years although it has been scaled back, and detectives have repeatedly stated they believe Miss Lawrence has been murdered. The case has been hampered by her tangled love life, which included relationships with married men who have been unwilling to disclose information to police.