Whistleblower who exposed school violence is banned from the classroom

Alex Dolan was given a 12-month ban after being found guilty of breaching pupils' trust by the General Teaching Council.

A panel ruled that the supply teacher, who also exposed apparent attempts to trick Ofsted inspectors, abused her position while recording secret footage at four schools in London and Leeds in 2005.

They rejected her claims that she acted in the public interest.

In a statement, Miss Dolan stood by her decision to make the documentary for Channel 4's Dispatches programme.

"This is a sad day for investigative journalism," she said.

"Programmes like Dispatches have an important role to play in drawing to the attention of the public matters of concern whether these are in hospitals, within the police force or in schools. I find it beyond comprehension that the GTC can spend three years investigating me when they should be looking on their own doorstep.

"Instead they have decided to sweep it under the carpet and persecute the whistle-blower."

Miss Dolan also accused the GTC of failing to face up to and deal with the serious problems that the film uncovered.

Among the revelations were that one school sent badly behaved pupils on a trip during an Ofsted inspection, and that pupils from another class were forced to have 26 different teachers in just six months.

The programme - Undercover Teacher - was aired in July 2005, but the case too more than three years to reach a full GTC hearing.