A science teacher who carried out secret filming in schools for a television documentary has been found guilty of unprofessional conduct by the General Teaching Council for England.

Alex Dolan shot the controversial footage for Channel 4‘s Undercover Teacher in July 2005. It showed badly behaved pupils and claimed teachers from other schools were drafted in to give Ofsted inspectors a false impression of higher standards.

Ms Dolan, who is now a full-time TV documentary producer and presenter, said the film, which was shot in four schools in London and Leeds, was justified on public interest grounds.

But a GTC ruling on Wednesday said: “We are satisfied that covert filming of pupils by a registered teacher is unacceptable, other than in wholly exceptional circumstances.

“For a teacher, who holds a privileged position in relation to pupils, to secretly film them for purposes of his or her own takes advantage of them and thereby breaches those pupils’ trust.”

The ruling said there had not been exceptional circumstances in this case and that Ms Dolan’s concerns could have been brought to the attention of the public in different ways.

Ms Dolan said after the verdict: “I am very disappointed that the GTC has chosen to discipline me rather than face up to and deal with serious problems that my film uncovered.

“The GTC conduct committee is out of touch with what really concerns teachers, parents and pupils, and have missed a chance to act as a catalyst for change.”

Ms Dolan has been suspended from teaching in state schools for one year. The GTC said she had not acted with malice and expected she would show better judgment in future if she returned to the classroom.