Education officials have promised to defend an Oxford comprehensive school which could face legal action following the expulsion of a teenage pupil.

It is understood that the boy, who attended the Cherwell School, in Marston Ferry Road, was expelled following an incident involving another pupil.

A letter written to the parents of the excluded pupil could be the subject of a legal challenge.

The law normally protects school reports and letters from libel actions.

A spokesman for the county council said: "Oxfordshire County Council and the Cherwell School are aware that parents of a pupil who used to attend the school may seek to challenge the wording used in a letter addressed to them at the time of the exclusion.

"We fully support the school in this matter and, if such a challenge is received, shall respond accordingly."

Legal actions against schools have soared in recent years but this is thought to be the first attempt at a libel case.

New freedom of information legislation means pupils can ask to see references written about them, then sue if they believe they are defamatory.

David Hart, general secretary of the National Association of Head Teachers, said a successful libel action against the Cherwell School would have an "enormous impact".

Headteacher Jill Judson was not available for comment on March 14 and the school was referring all inquiries to the county council's education department.

There are 1,600 pupils aged 11 to 18 at the school, which is split into two sites - north and south.