University Challenge became embroiled in more controversy after it emerged that a previous winning team had fielded a contestant who was not a member of the college he was representing.

Charles Markland, 23, revealed he had transferred from Christ Church to Balliol College, Oxford, halfway through last year's competition.

Christ Church ran out eventual winners, beating Sheffield University in the final.

Mr Markland claimed his team captain contacted a researcher on University Challenge concerning the possible change and was told that it was not a problem.

Oxford's Corpus Christi College - which beat Manchester 275 to 190 in the long-running quiz show's grand final - were stripped of the title by the BBC after it emerged team member Sam Kay had already graduated and was in full-time employment.

Mr Markland told the Press Association: "At the initial auditions in May 2007, my team captain informed the Granada television researcher in charge of conducting the written entry test for prospective teams that there was a possibility that I might be at a different college before the series had concluded filming.

"He was told that this was not a problem, nor a barrier to entry for our team."

He added: "Our captain contacted a Granada researcher on the programme again by telephone prior to the filming of the quarter finals to explain that I was indeed no longer at the same college.

"He was told that for continuity purposes, Granada wished us to field the same team regardless and that my move was not a problem."

Nobody from Granada Media was available for comment, but the company told the Daily Telegraph: "The University Challenge rules state that team members should all be students of the university or college for the duration of the recording of the series. This issue was not brought to our attention."