Search on for new EC internal auditor

Muis, a former Ernst & Young partner, played a key role in fighting corruption and championing reform within the EC.

He was also a strong supporter of Marta Andreasen, the former EC chief accountant and famed whistleblower, who was suspended from the commission after alleging serious weaknesses existed in its accounting procedures.

Muis has been the driving force behind stricter financial controls at the EC since he became head of the internal audit service, set up 2001, as part of a program of institutional reform.

His resignation, effective this month, has cast doubt over the level and pace of financial reform at the EC.