The chair of the European Parliament budgetary control committee has renewed calls to lift the immunity of EU’s anti-fraud chief Giovanni Kessler and allow an investigation by Belgian prosecutors into claims that he illegally recorded a phone conversation in 2012.

Kessler, who heads the EU’s anti-fraud office Olaf, could face criminal prosecution for secretly recording a phone call during an investigation that led to EU commissioner for health John Dalli leaving his post.

Belgian authorities demanded the European Commission lift his immunity in December 2014, but officials at the EU executive have yet to act.

The commission has refused to respond to questions on the delay or rumours that it has already lifted Kessler’s immunity.

“Due to legal reasons I’m not allowed to say a word on this,” commission spokesman Margaritis Schinas told journalists on Thursday.

Kessler is granted immunity in his role as Olaf chief. He is also entitled to bring “an action against his institution [EU commission] before the Court of Justice” if he considers that measures taken by the commission call into question his independence.

But the EP budgetary control committee chair, German center-right MEP Ingeborg Graessle, said on Wednesday (9 March) that the Belgian police should be allowed to investigate and put an end to the dispute.