A world famous concert pianist sexually assaulted boys who came to him for music lessons and filmed youngsters he abused from a Sea Cadet unit, a prosecutor has told a jury.

John Briggs, 65, went on trial at Bradford Crown Court today accused of offences against five boys, spanning a 24-year period, from 1969 to 1993.

The youngest was aged ten at the time of the alleged offence.

Briggs, who denies all the charges, sat in the dock as Nicholas Worsley, prosecuting, outlined each of the allegations made by the boys.

"He is a professional musician," Mr Worsley said.

"He plays the piano. He is a concert pianist.

"In the past he has taken private pupils for music lessons. During the course of those lessons he would sexually assault boys he was supposed to be teaching."

Briggs denied all the offences when he was interviewed by police, Mr Worsley told the jury of six men and six women.

He said the defendant told officers "the allegations were made up and it was all a vicious conspiracy against him".

Briggs, of Little Lane, East Morton, sat alone in the dock listening to the prosecution opening, wearing a jacket and tie.

He denies nine counts of indecent assault on a male and one of indecency with a child.

The trial continues.