Bill Rammell, the Education Minister, has been urged to hold an inquiry after the Quality Assurancy Agency was accused of condoning the upgrading of the exam results of failing students at De Montfort University.
The Times Higher reported last week that DMU had added up to 14 per cent to the marks of some pharmacy degree students.
Papers released under the Freedom of Information Act reveal opposition from academics and external examiners to the move, which lowered the pass rate in one exam to 21 per cent.
It emerged this week that while the pharmacy school was inspected in a university-wide audit last year, the QAA accepted the university's report, which found that the upgrading did not jeopardise standards.
The Government's new Teaching Quality Information website, intended to reveal concerns from external examiners, also failed to mention the issue.
Four external examiners wrote to the vice-chancellor to protest against the upgrade, but their summary reports make no reference to these issues, and approve all student grades.
Phil Willis MP said: "The time has come for the Minister for Higher Education to order a full inquiry into failures with the QAA and TQI."
The QAA said that its audit had found that DMU had investigated and had taken appropriate action.