Dominique Strauss-Kahn, a leading contender for the French presidency in 2012 and the head of the International Monetary Fund, will plead not guilty at Sunday afternoon arraignment after multiple charges were filed against him after allegations that he sexually attacked a hotel worker Saturday afternoon in New York.

He has been charged with committing a criminal sex act, attempted rape and unlawful imprisonment.

He denies all the charges against him, his lawyer Benjamin Brafman told the Associated Press. Beyond the not guilty plea that's all I can really say right now.

It was unclear why Strauss-Kahn was in New York. The IMF - a multi-national organization which lends to countries in financial difficulties - is based in Washington D.C.

Strauss-Kahn's wife Anne Sinclair said Sunday in a written statement she did not believe the charges.

I don't believe for a single second the accusations made against my husband. I don't doubt that his innocence will be established, she said.

John Lipsky the second-in-command at the IMF will assume Strauss-Kahn's functions as director general for however long is necessary, Le Figaro reported. The organization's board will meet Sunday evening.

The IMF remains fully functioning and operational, said Caroline Atkinson, Director of External Relations at the IMF. The IMF acknowledged the arrest and said it had no comment on the case.

On Saturday afternoon, Police officers in plain clothes belonging to the Port Authority of New York and New Jersey boarded an Air France plane Flight 23 at about 4:45 p.m. as it waited for takeoff and took him into custody.

Three police officers pulled Kahn from the plane's first-class cabin and turned him over to New York Police Department officers from the Midtown South precinct.

He is being investigated by the Special Victims Unit.

The incident is said to have taken place when a housekeeper entered Strauss-Kahn's room at the Sofitel hotel on West 44th street, the Post reported.