The BBC says it is investigating claims that a member of University Challenge's winning team broke the rules because he was no longer a student.
Corpus Christi College, Oxford, stormed to victory over the University of Manchester on the TV quiz last week.
PricewaterhouseCoopers has confirmed it employed team member Sam Kay, from Frimley, in Surrey, as a graduate accountant before the final was filmed.
The Manchester team have said they have "no desire" for a rematch.
According to newspaper reports, Mr Kay, who told viewers of the show he was studying chemistry, failed to get funding for a PhD and left the Oxford college after graduating last year.
He told the Observer: "I was a student when I applied to be on the show and on the day when we filmed the first two rounds, so I don't think I've done anything wrong."
We hope any decision does not detract from what was a thrilling final won by a truly tremendous team
Matthew Yeo, Manchester captain
But, according to the paper, he admitted he had left Oxford by the time the college had reached the quarter-finals.
The rules state that contestants must be a student throughout the filming and broadcasting.
PricewaterhouseCoopers told the BBC that Mr Kay was employed as a graduate accountant last September and is training to be a chartered accountant.
The final was filmed in November.
In a statement, the BBC said on Sunday: "We understand the allegations made and are taking the issue seriously.
"However, we need time to investigate fully, so we will do so and report our findings early next week."
Matthew Yeo, Manchester's team captain, said the Corpus Christi team were "deserving and worthy champions".
He said: "We thoroughly enjoyed our University Challenge experience and would like to thank all those who supported us on our road to the final.
"We hope any decision does not detract from what was a thrilling final won by a truly tremendous team."
Gail Trimble (l) and the winning team from Corpus Christi College
A spokesman for Oxford University said eligibility was a "matter for the BBC".
Its team was led by Gail Trimble, 26, who was dubbed the "Human Google" after Corpus Christi's victory in the quiz, which is chaired by Jeremy Paxman.
She scored two-thirds of her team's 1,200 points on the way to the final.
However, Mr Kay was an important factor in the showdown against Manchester, answering some crucial "starters for ten" which enabled his team to get onto the scoreboard when they trailed 70-0 in the early stages.
Corpus Christi eventually came through in the last few minutes to win by 275 points to 190 in a final watched by more than 5.3 million people.
It was the second time the Oxford college had won the competition, having also taken the title in 2005.
Founded in the early 16th Century, it is one of Oxford's smaller colleges, with fewer than 400 students.
Do you know this year's finalists? Do you attend either Manchester University or Corpus Christi College? Send in your comments using the form at the bottom of the page.
In most cases a selection of your comments may be published, displaying your name and location unless you state otherwise in the box below.
Here's a selection of your comments:
I support Matthew Yeo (our captain), we did brilliantly to get to the final. A rematch would mar our achievements. Corpus Christi deserved to win, thanks mainly to Trimble. I know I speak for my course mates when I say CONGRATULATIONS to both teams. Cori, Manchester
By last year are we to take that he graduated in summer 2008? As far as I am aware, if this is the case then his inclusion in the team is fully legitimate. The audition process is carried out in April/May of the previous year and the filming starts in the summer. Therefore, in this case the team would have started their campaign in summer 2008. Mr Kay would have been a student at the time of application and would have just graduated at the time of filming. To the best of my knowledge this is within the rules.
Fuss over nothing! Ex-challenger, Scotland
Personally, I'd rather think of the contestants as representatives of the colleges involved, within reason. The media shouldn't try to belittle the achievement of either team, as the true quality of University Challenge is the promotion of the quest for knowledge, not gain. Congratulations to all involved. Jon Scott, Buxton, U.K
Am I missing something? If they cheated by breaking simple and basic rules, shouldn't they have their winning status nullified and removed from any further competition? What sort of message does this send? Andrew Whittam, Hampshire
Yes, OK so he may have broken the rules. Having watched every time Oxford were playing, I have to say that Gail Trimble was the out and out forerunner of the team. Can she not be allowed to bask in the honour of her team's win? After all she answered more questions than anyone else. To take this away and taint the achievements of a talented individual is so typical of this country. Leave them be. Louella Palmer, Midhurst, West Sussex
I was a member of a team that was knocked out early on. When we were selected, we looked into this problem and were advised that even if we were in our final year, if we were intending to be studying at the university next year that it was ok. They did nothing wrong. The first round qualifying takes place while they are still at university but the finals take place later after they had graduated. I would be in the same position if my team had got further. nimblehippo, Harpenden, Herts
When I took part in 'University Challenge,' the first rounds were were recorded in June 1998. The later rounds and the final were played in November 1998, but as these were not broadcast until the following year, we were the "1999" champions. It therefore seems likely that, at the time Mr. Kay was recruited, took part in the auditions and first rounds, he was still a bona fide student, and was expecting to continue his studies until funding dried up at a later date.
Seems nobody likes a winner, especially if he's smart.
Sue Mitchell, Waltham (village) North East Lincolnshire
Manchester were well and truly beaten by Corpus Chritsi - it matters not about Mr K's status.
Good on Mr Yeo for not wanting to make a fuss and it was not as if it was a close contest!
Gail Trimble should take the credit due to her (ability, temperament and looks) Well Done all the participants. Some will always bellyache!!!
This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.