International Monetary Fund chief  Dominique Strauss-Kahn's New York City court appearance on sex charges has been postponed until Monday.

Strauss-Kahn, who had been considered a front-runner to vie for the French presidency next year under the Socialist Party banner, was expected to be arraigned Sunday after an alleged sexual assault on a maid at a New York City hotel.

But his lawyer William Taylor told reporters outside Manhattan Criminal Court on Sunday, "Our client willingly consented to a scientific and forensic examination tonight… at the request of the government, and in light of the hour we have agreed to postpone the arraignment until tomorrow morning."

Strauss-Kahn, 62, was yanked from an airplane moments before it was to depart for Paris from New York on Saturday, police said.

He’s expected to plead not guilty to charges of a criminal sex act, attempted rape and unlawful imprisonment.

Police confirmed Sunday that the maid had picked Strauss-Kahn out of a lineup.

Taylor and fellow lawyer Benjamin Brafman visited the Harlem police precinct where Strauss-Kahn was being held early Sunday afternoon. Brafman — who represented the late Michael Jackson in a child molestation case in 2004 and got a not guilty verdict for rapper "P. Diddy" Sean Combs on illegal weapons and bribery charges — refused to answer questions, only saying that his client "denies all the charges against him."

The IMF chief was removed from the first-class cabin of an Air France jet at John F. Kennedy International Airport on Saturday afternoon by officers from the Port Authority of New York and New Jersey, said Paul Browne, New York Police Department spokesman.

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A member of the NYPD crime scene unit enters the Sofitel hotel in New York after a maid accused IMF head Dominique Strauss-Kahn of assaulting her. ((John Minchillo/Associated Press))

It wasn't clear why Strauss-Kahn was in New York. The IMF is based in Washington, D.C., and he was due in Germany on Sunday.

Martine Aubry, leader of France's Socialist Party, said she was "astounded" by the news.

An IMF spokeswoman said in a release the organization remains "fully functioning and operational" but would not comment on the case.

German Finance Minister Wolfgang Schaeuble said on Sunday in a TV interview that another IMF official will be taking the place of Strauss-Kahn at a meeting of euro zone finance ministers in Brussels on Monday.

The ministers are set to discuss the European Stability Mechanism (ESM) draft — a planned permanent bailout fund for the countries that use the euro. A decision is expected in June.

$3,000-a-night suite

Strauss-Kahn checked into a $3,000 US-a-night room at the luxury Sofitel hotel not far from Manhattan's Times Square on Friday afternoon, police said.

A 32-year-old woman told police she entered Strauss-Kahn's suite at about 1 p.m. Saturday and he attacked her, Browne said. She said she had been told to clean the suite, which she had been told was empty.

The woman told police Strauss-Kahn emerged from the bathroom naked, chased her down a hallway and pulled her into a bedroom, where he began to sexually assault her. She said she fought him off, then he dragged her into the bathroom, where he forced her to perform oral sex on him and tried to remove her underwear.

The woman broke free and told hotel staff what happened, authorities said. When detectives arrived later, Strauss-Kahn had already left the hotel, leaving behind his cellphone and other items, Browne said. 

Strauss-Kahn has faced controversy before. Last year, he admitted to an error in judgment for having an affair with a subordinate.

French journalist Anne Sinclair, Dominique Strauss-Kahn's wife, issued the following statement Sunday:

"I do not believe for one second the accusations brought against my husband. I have no doubt his innocence will be established."

France woke to the bombshell news Sunday to surprise and a degree of caution. Online commentators questioned whether the incident could have been part of a smear campaign by the unpopular President Nicolas Sarkozy, whose political fortunes have been flagging, against his main rival in the race for next year's presidential elections.

The arrest could completely shake up the race for president, and throw the long-divided Socialists back into disarray about who they could present as a challenger to Sarkozy.

"It's a cross that will be difficult for him to bear," Dominique Paille, a political rival to Strauss-Kahn on the centre-left, said on BFM television. "It's totally hallucinating. If it is true, this would be a historic moment, but in the negative sense, for French political life."

After his arrest, Strauss-Kahn was interviewed by the police department’s special victims unit. The maid was treated for minor injuries.

Headed to Berlin

Strauss-Kahn was supposed to be meeting in Berlin on Sunday with German Chancellor Angela Merkel about aid to debt-laden Greece, and then join EU finance ministers in Brussels on Monday and Tuesday.

Strauss-Kahn took over as head of the IMF in November 2007. The 187-nation lending agency is headquartered in Washington and provides help in the form of emergency loans for countries facing severe financial problems.

He won praise for his leadership at the IMF during the financial crisis of 2008 and the severe global recession that followed. More recently, he has directed the IMF's participation in bailout efforts to keep a European debt crisis which began in Greece from destabilizing the global economy.

Strauss-Kahn, dubbed DSK in France, was seen as the strongest possible challenger to Sarkozy but has not declared his candidacy.

The New York accusations come amid French media reports about Strauss-Kahn's lifestyle, including luxury cars and suits, that some have dubbed a smear campaign.

He sought the Socialist Party's endorsement in the last elections, in 2007, but came in second in a primary to Ségolène Royal. Royal, the first woman to get so close to France's presidency, lost to Sarkozy in the run-off.

Royal said Strauss-Kahn has the right to the presumption of innocence.

"My thoughts go to the man in this difficult time and to his family," she said. "We are in a democracy and must let justice do its work. Everybody must stay calm."

With files from CBC News