Moves are afoot in Germany to strip President Christian Wulff of his immunity from prosecution.
The public prosecutor in Lower Saxony, where Mr Wulff was previously the chief minister, has asked the federal parliament to do so.
The prosecutor said on Thursday the president is suspected of improperly accepting and granting benefits. He has also been accused of trying to bully the Bild newspaper not to run the story.
The BBC reports Mr Wulff, 52, has denied any wrong-doing.
At the centre of the row is a report that Mr Wulff received a low interest loan of 500,000 euro ($US649,000) from the wife of a wealthy businessman in October 2008.
Mr Wulff was later asked in the Lower Saxony parliament if he had had business relations with Egon Geerkens. He said he had not, but made no mention of his dealings with Mr Geerkens's wife.