A PRISON worker has gone on trial accused of a string of sex offences against girls going back to the 1990s.

John Cornwell denies 13 charges of indecent and sexual assault, and sexual activity in the presence of a child.

The married 53-year-old, from Darlington, claims one of his accusers has encouraged others to make allegations.

Prosecutor Richard Bennett, at Teesside Crown Court, told a jury that the allegations were supported by police discoveries at Mr Cornwell's home.

After official complaints were made in March last year, pornographic videos were found during a search.

Two of the girls claimed he watched the films in front of them and one said he "lifted his willy up and down".

In an apparent reference to sex toys on the movies, she said in an interview with detectives: "There were boys and girls with plastic sticks pretending to be willies."

The jury of seven men and five women were today (May 7) shown a recording of the interview of one of the complainants.

She said Mr Cornwell watched pornographic films and masturbated when she was in his home in West Auckland Road.

Mr Bennett described an attempt Mr Cornwell made to have her touch him as "an early sign of what the defendant's interest is".

Allegations were first made against him in 2004 and again two years later, but the police were never involved.

Mr Bennett said matters resurfaced on New Year's Eve 2011 and official complaints were finally made several months later.

"In interview, he categorically denied all the allegations," Mr Bennett told the jury.

"He suggested [one of the accusers] was doing this against him and running some sort of campaign against him by putting ideas into the heads of the others to lie about him and what he had been doing to them."

Mr Cornwell, who works as a prison support officer at a Young Offenders' Institution in North Yorkshire, faces a trial that is scheduled to last six days.