A university has been investigated for fraud after a member of staff was overpaid by £75,000.

The University of Sussex's audit committee was tasked to look into the “long term overpayment” - which was not reported by the recipient.

While they found no “systematic collusion or exploitation” of the finance system, the staff member has been ordered to pay back the five-figure sum.

Meanwhile a student group has demanded answers after raising concerns about the error.

Michael Segalov, Sussex Students Union communications officer for 2014/15 and member of Sussex Against Privatisation, said: “In a climate of further cuts to higher education, and the David Willetts refusing to rule out further fee increases, it is extremely disconcerting to hear that Sussex University cannot keep on top of their finances.”

The university's Fraud Response Plan was acted on after the “irregularity” was reported by finance staff on March 14.

An investigation followed into what was described as a “relatively long term overpayment” amounting to around £75,000.

It was subsequently decided the incident was not to be treated as fraud but instead a financial irregularity.

A university spokeswoman said: “The investigation revealed no systematic collusion or exploitation of the system.

“However processes have been revised since the discovery of the event to reduce or eliminate the likelihood of such an event occurring.”

Rather than launching legal proceedings it was decided to draft a written agreement for repayment from the member of staff.

The university has already received a one-off repayment of £15,000 and has recovered around £12,000 in pension and tax costs.

The remaining balance is to be repaid in a monthly deduction from salary.

The audit committee's report said: “The complete repayment will take some years but our lawyers advised that the agreed plan was more likely better than going to law on this issue.

“The HR file of the individual is marked so that if the employee leaves, an alternative arrangement (e.g. one-off recovery from any ERVS payment and/or pension lump sum if appropriate) can be made”.