Strauss-Kahn had been under house arrest for weeks in a Manhattan loft on six million dollars (£3.7m) in cash and bond.
The charges, which include attempted rape, have not been reduced, but the move signals that prosecutors do not believe the accusations are as ironclad as they once seemed.
Investigators have come to believe that the woman lied about some of her activities in the hours around the alleged attack and about her own background, a law enforcement official said.
Prosecutors think she lied about details on her application for asylum in the US, including saying she had been raped in her native Guinea, the official said.
The French politician’s passport remained surrendered, and he will not yet be allowed to leave the country. One of his lawyers, Benjamin Brafman, said Strauss-Kahn would be free to travel within the United States.
The 32-year-old hotel maid accused Strauss-Kahn of chasing her through his luxury suite in May, trying to pull down her pantyhose and forcing her to perform oral sex.
“It is a great relief,” said another of Strauss-Kahn’s lawyers, William Taylor, adding that the case underscores “how easy it is for people to be charged with serious crimes and for there to be a rush to judgment”.
“It is so important in this country that people, especially the media, refrain from judgment until the facts are all in,” he said.
The accuser’s lawyer did not back down on the seriousness of the charges.
“From day one she has described a violent sexual assault that Dominique Strauss-Kahn committed against her,” lawyer Ken Thompson said.
“She has described that sexual assault many times, to prosecutors and to me, and she has never once changed a single thing about that encounter,” he said.
He referred to media reports that his client was involved with a drug dealer, calling them lies.
Strauss-Kahn arrived at the courthouse and strode confidently up the granite steps with his wife, French journalist Anne Sinclair, at his side. He wore a dark grey suit, and she a white jacket.
After the hearing, he walked slowly out of the courthouse with his arm on her shoulder, smiling slightly at the throng gathered outside.
The New York Police Department, which investigated the case, declined to comment. The woman’s lawyer did not immediately return a telephone call seeking comment.
“There will be serious issues raised by the district attorney’s office and us concerning the credibility of the complaining witness,” Benjamin Brafman, a lawyer for Strauss-Kahn, told the Wall Street Journal.
If the case collapses, it could once again shake up the race for the French presidency.
Strauss-Kahn, a prominent Socialist, had been seen as a leading potential challenger to conservative President Nicolas Sarkozy in next year’s elections – until the New York hotel allegations embarrassed Strauss-Kahn’s party and led to his resignation from the IMF.
“Those who know Dominique Strauss-Kahn will not be surprised by this evolution of events,” one of his French lawyers, Leon Lef Forster, said in Paris. “What he was accused of has no relation to his personality. It was something that was not credible.”
Former French finance minister Christine Lagarde succeeded him as head of the IMF this week.