Police investigating historic sex offences including rape at one of Britain's top schools have arrested a former head of department.

The man, in his 80s, taught for several decades at Stowe School in Buckinghamshire, whose ex-pupils include Sir Richard Branson.

The ex-master was arrested by police on suspicion of rape and indecent assault at the £53,000-a-year school.

The investigation was triggered after a woman in her 50s claimed she had been sexually assaulted by him when she was at the former boys' school, which admitted girls into its sixth form in the 1980s.

Police are understood to have interviewed other female former pupils taught by the man during the late 1980s, leading to his arrest in November last year.

Other former pupils at Stowe, founded in 1923, include the late Hollywood star David Niven, Superman actor Henry Cavill and film director Matthew Vaughn.

Two of Prince Harry's former girlfriends, Chelsy Davy and Cressida Bonas, attended Stowe as it opened its doors to more girls before going fully co-educational in 2003.

More recently, the school has been famed for producing sporting talent including England cricketer Ben Duckett and rugby prodigy Henry Pollock.

A Thames Valley Police spokesman said: 'We have received a report of non-recent sex offences in the late 1980s at Stowe School.

'An investigation has been launched and a man in his 80s from Bicester has been arrested on suspicion of rape and indecent assault. He has been bailed while our inquiries continue.

'The investigation remains ongoing and is being progressed thoroughly, with extensive inquiries continuing, which has contributed to the length of the investigation.'

Other private schools recently hit by historic child abuse allegations include Kingswood School in Bath, which wrote to former students inviting them to come forward after an ex-pupil alleged an assault in the 1990s, and Tony Blair's former school Fettes College in Edinburgh.

Fettes governors this year issued an unreserved apology to those who suffered abuse at the school from the 1950s to the end of the 1980s.

Stowe headmaster Anthony Wallersteiner said: 'We are aware of an investigation into a former member of staff. We deplore sexual, physical and emotional abuse and acknowledge damage it can cause.

'We encourage all victims of abuse to come forward. The school has been inspected by the Independent Schools Inspectorate and the report reflects on the excellent quality of pastoral care and our commitment to ensuring all safeguarding standards are met and strictly followed.'