A perverted teacher posed as an interviewer for a lads mag to get a girl's mobile number before subjecting her to a stream of filthy text messages.

Jamie Bell, 52, a coordinator of Brighton's Fairtrade campaign group, got the 16-year-old's mobile number after calling her on her home phone and saying he was a journalist for the men's magazine FHM.

The victim, who cannot be named for legal reasons, became suspicious when the 'interview' became sexually explicit.

She then received a series of filthy messages from Bell.

Magistrates in Brighton grimaced today as dozens of stomach-turning texts were read out in court before the court clerk eventually said: "I think we've heard enough."

Dressed in a smart dark brown suit, silver-haired Bell - an IT and media teacher - hung his head as the messages were read aloud.

One of the texts asked if the girl would meet him when she was on half term.

Bell, who lives with his mother in North Gardens, Brighton, claimed not to have known the girl was 16.

He pleaded guilty to harassment after plaguing the girl in December last year.

His defence said his work with the Fairtrade Foundation was evidence that he was not of bad character.

Magistrates handed him a four-month prison sentence, suspended for 12 months, as well as 200 hours of unpaid community work and £60 costs.

Bell is one of the main organisers of Brighton's Fairtrade Foundation, which has been in existence for almost 15 years.

He was behind a number of events which have celebrated Brighton's status as a Fairtrade city and is a staunch campaigner for introducing Fairtrade produce into more shops across the city.

Bell represented the group during visits, including one at Cardinal Newman Secondary School, Hove, by a cocoa farmer from Belize, Central America, who had been sponsored by the Fairtrade Foundation.

The seminar was attended by children from schools across the local area.

He has also welcomed farmers from Ethiopia who have visited Brighton to discuss the Fairtrade movement and how it affects their lives.

Bell has previously written articles in the media about the Fairtrade movement and encouraged Brighton celebrities, including Gaz Coombes and Julie Burchill, who have backed his calls to shop with a conscience.

And he was a judge in a Fairtrade cookery competition run by Brighton and Hove City Council and supermarket chain Co-op in primary and secondary schools across the city.