Clearer and "more emphatic" guidelines are required for governing bodies in higher education, the National Audit Office has said.
An NAO investigation into events which led to the resignation of Neil Merritt, the former vice chancellor of Portsmouth University, found current codes for governors wanting.
Guidelines from the Higher Education Funding Council for England and the Committee of University Chairmen were insufficient to prevent "serious weaknesses" in the handling of allegations of impropriety or mismanagement, an NAO report says.
But John Pickering, the university's former deputy vice chancellor forced to resign after a management review in 1994, said the NAO's recommendations do not go far enough.
The report focuses on concerns raised from 1992 about Mr Merritt's expenses and a management style which led to his resignation in December 1994.
Evidence had been found to support allegations that Mr Merritt had claimed for club class air travel to Egypt and to the Far East when he had travelled economy class, keeping the difference, a total of Pounds 1,457.
After interviewing Mr Merritt, university officials recorded that he had explained that the surplus on the tickets had been used to fund his expenses and he had consequently not submitted a full claim for expenses.
They accepted Mr Merritt's explanation, but reprimanded him for "serious errors of judgement".
The NAO investigation nevertheless concludes that "errors of judgement" were made by governors in the handling of the irregularities "and these and other aspects of the governance of the university did not comply with accepted good practice".
A decision taken by the governing body's audit committee not to notify the funding council of the allegations was wrong.
"The funding council could have assisted the governors in their decision-making and could have offered advice on the seriousness of the matters discovered," the report says.
They were "unwise" to delay a full audit inquiry until after the claims had been raised with Mr Merritt.