Students at Oxford Business College must resit their summer exams after a probe into "irregularities".

And the college had its approved centre status removed  by a leading examination body after claims that questions were leaked to students.

The Institute of Commercial Management held an investigation into the college, in King Edward Street, after being contacted by tutor Kerri Wilkinson. She alleged she was given leaked exam questions in advance and told to "focus" students on the answers.

The institute says it is "satisfied that the allegations have substance" and has announced it is withdrawing its "approved centre status".

ICM chief executive Alistair Somerville Ford told the Oxford Mail none of the June exam scripts from Oxford Business College candidates would be marked "to protect the integrity of the Institute's examinations".

He added: "Arrangements will be made for candidates to re-sit their examinations free of charge in September at an alternative centre in Oxford."

Stanley Hunter, the college's principal, said: "I refute the allegations that have been made. There is no substance in them."

Mr Hunter, who also owns Pitman Training Centres in St Aldates, declined to comment further.

Canadian Ms Wilkinson, 27, joined the college in February to teach information technology, including the ICM diploma in business studies.

She said she called the Institute's managing director to voice concern that she had been shown the exam question in advance. She said: "The ICM has been very supportive. I'm grateful this matter has been properly investigated and happy with the way things have turned out."

Mr Somerville Ford said: "The Institute's education committee has investigated the allegations and is satisfied that the allegations have substance."

Ms Wilkinson, of Summertown, recently left the college. She has also made separate allegations to another examining body, the London Edexcel Foundation.

Hanneke Sharif, spokesman for the foundation, said: "We have stringent security procedures and all allegations of misconduct, however slight, are fully investigated."

The private college, off High Street, offers a range of business and management courses and attracts large numbers of overseas students. In 1994 it also acquired the Marlborough Secretarial College, one of the oldest secretarial colleges in Britain.

Converted for the new archive on 30 June 2000. Some images and formatting may have been lost in the conversion.

Update: Oxford Business College appealed this decision and had its status by the ICM reinstated. No students had to resit their exams and Mr Hunter said the allegations were untrue.