A French court summoned Christine Lagarde, the managing director of the International Monetary Fund (IMF), to testify in a corruption investigation into alleged misuse of public funds when she was France\'s finance minister.On Wednesday, news website Mediapart reported that Lagarde was due to appear before French magistrates on May 23.The investigation was launched in 2011, press tv reported.Lagarde is suspected of misusing public funds when she overruled objections from advisers in 2007 to go ahead with arbitration between Bernard Tapie, a former minister of city affairs, and the collapsed bank Credit Lyonnais, which was formerly state-owned.The arbitration ended with the state paying 285 million euros (about $371.70 million) of taxpayers\' money to Tapie.Tapie sued the French government for compensation after the disgraced ex-minister sold his stake in sports company Adidas to Credit Lyonnais in 1993. He claimed the bank defrauded him after it resold his stake for a much higher sum.Tapie resigned as minister of city affairs in 1992 over corruption charges. He was later sentenced to two years in prison.Both Lagarde and Credit Lyonnais, now part of Credit Agricole, have denied any wrongdoing.Mediapart also revealed in December 2012 that France\'s budget minister Jerome Cahuzac had a secret Swiss bank account in his name. On March 19, Cahuzac resigned after prosecutors opened a probe into the issue.