IMF Managing Director Dominique Strauss-Kahn was detained in New York Saturday night after allegedly sexually assaulting a maid in his hotel.
The chief was apprehended in the first-class section of a flight heading to Paris, just minutes before departing John F Kennedy airport, a New York police spokesman said.
The woman who filed the complaint against Strauss-Kahn, 62, was a 32-year-old chambermaid who fled the room after the incident.
Police said the alleged incident took place at the upscale Sofitel hotel on West 44th Street near Times Square. The NYPD's Special Victims Unit is investigating the case.
Strauss-Kahn had not been charged.
The arrest promises to stir up politics in France, where Strauss-Kahn is believed to be considering challenging French president Nicolas Sarkozy in next year's election.
Polls have shown he has strong odds of defeating Sarkozy.
This is the second time since he took the helm of the IMF in November 2007 that Strauss-Kahn has faced allegations of misconduct.
In 2008, he had a relationship with Piroska Nagy, a female economist at the IMF. An investigation by the IMF board, released in October 2008, concluded that while he had made a serious error of judgment, he shouldn't be fired.
Strauss-Kahn took over the International Monetary Fund in 2007 for a five-year term, scheduled to end next year.
Before that, he was a French finance minister, member of the French National Assembly and a professor of economics at the Institut d'Etudes Politiques de Paris.
The IMF declined to comment.