French authorities have formally opened a negligence investigation into Christine Lagarde, the head of the International Monetary Fund (IMF).
She has been questioned about her role in awarding 400m euro (£318m; $527m) in compensation to businessman Bernard Tapie in 2008. She denies wrongdoing.
Ms Lagarde, 58, was finance minister in President Nicolas Sarkozy’s government at the time of the award.
Mr Tapie supported Mr Sarkozy in the 2007 presidential election.
He was once a majority shareholder in sports goods company Adidas but sold it in 1993 in order to become a cabinet minister in Francois Mitterrand’s Socialist government.