A teacher who was assaulted by a pupil with a history of bad behaviour at a secure unit began a High Court bid yesterday for damages from Oxfordshire County Council.

Sharon Millward, of Worsley, Manchester, said she was suffering severe post-traumatic stress disorder as a result of the incident in April 2000.

She alleges that the county council, which ran the Thornbury House Secure Unit in Kidlington, knew the teenager who assaulted her had a long history of violence towards teachers and social workers, but failed to tell her.

Barrister Simon Dyer told the court that Mrs Millward was assaulted by the boy when he was 13 on April 6, 2000.

She was alone with him in a locked classroom when he attacked her, injuring her groin and arms.

Mrs Milward said she was also taking action because the mental trauma she suffered was ruining her life.

Mr Dyer told Mr Justice Hughes the boy, who can only be referred to as 'S' for legal reasons, was taken into care in 1996, and since that date had a "history of violent behaviour".

He told the court there was a recommendation S needed two people to supervise him.

"This is a boy who was targeting female members of staff for abuse and violence," said Mr Dyer, who added that the teenager had spent three weeks at Thornbury eight months before the assault. "They had him for three weeks, and guess what?" asked the barrister.

"He had targeted and abused two members of staff while he was there."

He added that the fact S was violent was borne out by the council's own record of his behaviour.

A report suggested the pupil had shown "aggressive, antisocial behaviour" and was frequently in trouble.

Mr Dyer added that acts of recorded violence included attacking two social workers, one of whom was driving, when they were taking him to court, kicking and punching teachers, and robbing an elderly woman.

Giving evidence, Mrs Millward said she would have thought twice about being left alone with the boy had she known of his violent tendencies and that he was capable of making unwanted sexual advances.

But John Norman, for the council, said even if she had been fully informed of the boy's behaviour, she was likely to have continued to teach him.

He told her: "As an experienced teacher, that's the kind of thing you could deal with without much concern."

Mrs Millward, who said she had received restraint training, replied: "I was on my own, locked in a room. I wasn't given the opportunity to make that decision or discuss it."

The case continues.