Bomb hoaxer Michael Gavin was jailed for 15 months at Croydon Crown Court last Wednesday.

The court was told the 41-year-old twice caused chaos with bogus phone calls and later tried to withdraw his confession.

And that he had never recovered from being the victim of an armed robbery in 1986 and couldn't beat depression.

Prosecuting, Hamish Reid said Gavin, of Graham Road, Mitcham, rang up Faversham House, a publishing company, claiming that a bomb had been planted in the nearby Somerfield store car park in Addington Road, South Croydon.

Mr Reid added: "The supermarket had to be evacuated. Then he pretended to be a CID officer and phoned the managing director of Faversham House again, saying there was a bomb there.

"That place was evacuated. Police traced the number and he was arrested at his home.

"At an interview in the police station, he denied having made the calls. And he denied knowing anything about Faversham House, but it turned out he had worked for the group for some months. He later accepted that he had been employed there."

David Ryan, defending, said an armed robbery had had a lasting effect on Gavin. Mr Ryan added: "He slipped into a cycle of depression, made worse by drinking. He is at high risk of self-harm in custody or in the community."

Judge Cedric Joseph, who earlier rejected Gavin's bid to change his plea from guilty to not guilty, told him: "What you did amounts to a serious offence.

"Bomb hoaxes always have to be taken seriously by the authorities. It causes a great deal of disruption and concern and they are a waste of police time."