US prosecutors have charged the head of the IMF, Dominique Strauss-Kahn, with a criminal sexual act, attempted rape, and unlawful imprisonment.
The charges are in connection with an alleged assault on a hotel maid on Saturday, at a hotel near Times Square in New York where Strauss-Kahn was staying.
He is expected to appear before a judge on Sunday.
The news agency Reuters says it has received an email from his lawyer saying that he will plead not guilty to the charges.
Frenchman Strauss-Kahn was taken off an Air France plane at JFK airport minutes before it was due to take off.
Detectives said he had cooperated fully with their enquiries.
Strauss-Kahn has political aspirations. He ran for leadership of the French Socialist Party in 2006 but was unsuccessful.
He is also considered a possible candidate for the French presidency.
He has won praise for his role at the IMF, steering it through difficult times throughout the financial crisis.
This incident comes at a crucial time for Strauss-Kahn, and could derail any ambitions that he might have to take over France’s top job.