The chairman of the Quality Assurance Agency has misled a committee of MPs, according to the troubled exam board Edexcel.
QAA chairman Christopher Kenyon told the House of Commons education select committee in June that the agency was monitoring Edexcel's functions as a higher education awarding body after it was found to be "ultimately responsible" for a failing HND course at Newham College.
But this week Edexcel denied the claims and said it would be taking up the matter with the QAA and the select committee.
Mr Kenyon made the claims in a letter to select committee chairman Barry Sheerman MP regarding the QAA's decision to condemn Newham's business and management courses as failing, after the college was found during a teaching quality assessment to have run an Edexcel course without Edexcel's validation.
Newham complained to the QAA that this validation problem was due to an administrative error by Edexcel, a result of confusion over validation dates, and said the decision to brand the courses as failing was perverse.
Mr Kenyon wrote to Mr Sheerman: "We found the reported weakness to be serious in its implication for quality and standards. Responsibility for this resided ultimately with Edexcel, which is the awarding body.
"Edexcel has acknowledged its fault... and has moved to tighten up its procedures. QAA is monitoring the changes it has introduced... we will continue to monitor the way in which Edexcel courses are validated."
In a letter to The THES this week, Edexcel external relations head Frank Wingate said: "We certainly did not acknowledge any fault for any error... QAA has confirmed that it is not monitoring the 'way in which Edexcel courses are validated' nor has it requested we make changes."
Mr Wingate said that Newham alone was responsible and that Edexcel agreed to "retrospectively" validate the course after the QAA discovered the problem.
He said he did not believe that Mr Kenyon set out to mislead the committee and that his letter could be subject to misinterpretation, but that Edexcel stood 100 per cent behind its version of events.
QAA chief executive Peter Williams said he was content that Mr Kenyon's letter was "entirely accurate". But, he said: "Mr Kenyon is writing to Barry Sheerman to provide him with additional information which will clarify the position."
Newham principal Martin Tolhurst said that Edexcel knew students were registered on the programme when it was supposedly "not validated" so it was at fault.
But he said that his quarrel was not with Edexcel, which "did put matters right", but with the QAA "whose treatment of the issue was completely disproportionate to its significance".