A New York judge has dismissed sexual assault charges against former International Monetary Fund chief Dominique Strauss-Kahn, one day after prosecutors moved to have them dropped.

The ruling Tuesday ends the criminal case against Strauss-Kahn, who was arrested in May on suspicion of raping a hotel maid in New York City.

On Monday, prosecutors said the evidence did not prove that Strauss-Kahn engaged in a forced sexual encounter with the woman. They expressed concern about the accuser's reliability, saying she has not been truthful on “great and small” matters and said they could not ask a jury to believe her, when they no longer believed her themselves.

Guinean-born Nafissatou Diallo accuses the former IMF chief of sexually assaulting her when she went to clean his room at a Manhattan hotel on May 14. Strauss-Kahn's lawyers deny the allegation and suggest that any sexual encounter was consensual.

Protesters gathered outside the courthouse Tuesday, criticizing the move to drop the charges.

Before Strauss-Kahn appeared in court Tuesday, the judge denied Diallo's request for a special prosecutor to continue the criminal case. Her attorney argued the Manhattan District Attorney's office was biased.

The case faltered in late June when prosecutors revealed inconsistencies in Diallo's account of what happened. They also disclosed that she had fabricated a story about being raped in her native Guinea for her U.S. asylum application.

Efforts to clarify what happened between Strauss-Kahn and Diallo will likely continue in civil court, where she has sued him. He also faces an investigation in France into another attempted rape accusation.

Before the incident, Strauss-Kahn was a leading contender to challenge French President Nicolas Sarkozy in an election next year. He resigned his IMF post after being arrested on the rape allegations, which significantly eroded his support among French voters.

He has been free on bail since a brief period of detention after his arrest.