In early 1999 Commission President Jacques Santer admitted that there had been irregularities, but threatened to resign if Parliament exerted further pressure.
[4] In response, Parliament called for a committee of independent experts to look into ways of improving financial management and control.
After receiving the first report of the so-called Wise Men in March 1999, the Santer Commission decided to collectively resign.
The basis for establishing the IAS was recommendation 35 of the Wise Men's report[6] proposing A professional and independent Internal Audit Service.
The Commission task force worked with the European Court of Auditors, the Wise Men committee, the World Bank and the EIB in developing the new control framework.
The IAS serves under the leadership and responsibility of the Internal Auditor of the Commission, a position created in the Financial Regulation.
After setting up the IAS and guiding it through its first three years, Jules Muis resigned from his post as of March 2004 and was replaced by Walter Deffaa.
Between 2009 and 2023 the function of the internal auditor of the Commission and director-general of the IAS was entrusted successively to Brian Gray, Philippe Taverne and Manfred Kraff, who had all previously been deputy directors general of Directorate-General for Budget and the accounting officers of the Commission (equivalent to CAO, chief accounting officer).