A cathedral helper was jailed for 16 years today after a judge branded him a "serial sex abuser" for more than 30 offences against boys over 28 years.

Terence Banks, 62, assaulted a dozen boys while a helper at Chichester Cathedral, where his father was treasurer.

Banks, a former BBC production worker, was cleared at Lewes Crown Court of a serious sexual offence between August 16 1975 and August 15 1978 on a 15-year-old boy.

But after a three-day trial, a jury convicted him of another serious offence against a 13-year-old boy between January 1 1971 and December 31 1973.

Banks had denied both charges, But at a previous hearing Banks had already admitted 31 sex offences against boys and young men.

Sentencing him, Judge Richard Brown said: "You were a manipulative and wicked serial sexual abuser of boys and young men. You used cathedral activities as a cloak to cover your targeting of potential young victims.

"You totally and utterly corrupted these young boys for your own perverted sexual gratification for over 28 years."

On the first day of the trial, the jury heard how Banks met boys while running an organisation made up of former pupils of a local school. The group helped Banks stage the annual Chichester Cathedral festival.

Banks, who had a flat in Hammersmith, London, was also a well-known cathedral helper who acted as a steward during services and at coffee mornings held after worship.

The court heard how in the summer of 1972, Banks, of Little London, Chichester, sexually assaulted a 13-year-old boy while on a water skiing trip at a gravel pit near Chichester.

Later the same day, at his parents' house in Cathedral Close within the cloisters of Chichester Cathedral, he assaulted the boy as he took a bath.

The victim, now 42, told the court: "I locked the bathroom door and took out the key but then the door opened and Mr Banks was there. I was terrified. I stood up and got out of the bath and he grabbed me. I was very scared."