It happened he while giving demonstrations at a secondary school in what was described as a “disgraceful” abuse of trust.

David Blaxhall’s candid camera managed to video up a 14-year-old’s skirt in a classroom.

But when the strategically placed camcorder was spotted, pupils turned the tables on him by recording his actions on a mobile phone.

Forty-nine-year-old Blaxhall, formerly of Todmorden, who set up Calderdale Sound community radio station in the town in the mid 1990s, described it as a “morality bypass” after his wife left him for another man and he was at a low ebb, Preston Crown Court heard.

Blaxhall, now of Longridge Heath, Brierfield, pleaded guilty to four charges of taking indecent photographs and three of making indecent photographs.

He was given a community order, involving three years supervision and a requirement to go on community sex offender programme.

The first four offences dated to 2006, at a school in Blackburn.

Blaxhall ran a project for a number of schools, training pupils on radio broacasting.

Hugh McKee, prosecuting, said around 20 pupils were involved in the project, relating to the offences. A number were girls.

One of them became concerned that Blaxhall was using a camcorder beneath the desk where he was sitting, to film her. She spoke to some of the other pupils about it, he said.

“The pupils decided not to do anything until they had proof.

“The next day she could see the defendant was again using a camcorder beneath the desk to film her lower body.

“On this occasion another friend used a mobile phone to record what the defendant was doing. In their view, they had their proof.”

The pupils went to the project co-ordinator and other members of staff were told. Blaxhall denied any wrongdoing.

The police were contacted and the 41-minute video tape was found on the front passenger seat of his car. Seven stills were taken from the video.

His home was searched and at least two computers were taken away.

A number of indecent images were found on them – four at level one, two images at level two and one image at level three of seriousness.

The photographs taken at the school were in the category of level one, the least serious category.

Blaxhall, who had worked for local radio stations in East Lancashire, was previously of good character.

Gerard Doran, defending, said Blaxhall had been troubled by the offences.

“Since his arrest he described it, in his own words, as a period of time ‘'when my morality and good character had a bypass’.”

Mr Doran said “It was a time when his wife had left him for another man and he found himself at a very low ebb. He recognises he has acted within a moment of madness.

“It wasn’t for a very long time that he was called to attend the lower court.

“He suffered significantly with feelings of paranoia every time the door would knock or the postman would arrive.