A boarding school housemaster who was alleged to have sexually assaulted a boy at a school near Abingdon 11 years ago was yesterday jailed for 10 years for raping boys in his care.

Anthony Bulley, 39, systematically preyed on boys aged between 11 and 14 while he was employed as head of care at Stony Dean School, in Amersham, Buckinghamshire, Oxford Crown Court heard.

The court was told he lured the boys to his flat, which was attached to a boarding house.

Bulley admitted six offences, including rape and sexual assault, on four boys between 2002 and the end of last year.

Another 11 charges, involving three other boys, were denied by Bulley and allowed to lie on file by the CPS.

In 1994, he was investigated following an allegation of a sexual nature made by a boy at his previous place of work, Bessels Leigh School, near Abingdon, an independent residential school for boys.

Bulley worked under the name Nigel Bulley -- his middle name -- at Bessels Leigh. However, the complaint there did not lead to a prosecution.

Thames Valley Police spokesman Victoria Bartlett said yesterday that the allegation had been investigated, but there was not sufficient evidence to take the case to court.

However, police interviews from that inquiry were used in yesterday's court case. She added that police would not be re-examining the allegation.

The earlier allegation was not picked up when Bulley started work at Stony Dean as Anthony Bulley, the court was told.

Christopher Donnellan, prosecuting, said: "At the time (1994), the defendant was using the name Nigel Bulley.

"This may have been why this information did not carry forward to his next place of work."

In 2002 he was investigated again, following a complaint from a boy's mother, the court heard.

Police later decided there was insufficient evidence, but it was made clear to Bulley that he was to view this as "a warning across his bows", said Mr Donnellan.

But he kept on abusing boys, sweet-talking them into his quarters before molesting them. He admitted raping two boys and sexually assaulting two others.

Jailing him for 10 years, Judge Julian Hall told Bulley: "You have polluted the waters of decent, hard-working teachers.

"You have let an admirable group of people down."

The judge banned Bulley from working with children for the rest of his life.

Buckinghamshire County Council, which runs Stony Dean School, said after the hearing that an independent inquiry would start next month.