New York City prosecutors say they are asking to dismiss all criminal charges against Dominique Strauss-Kahn because they aren't sure beyond a reasonable doubt that the hotel maid who accused him of sexual assault is telling the truth.

The Manhattan district attorney's office says in court papers filed Monday that accuser Nafissatou Diallo repeatedly gave false information to investigators and grand jurors about her life, her past and her actions after her encounter with Strauss-Kahn, the former head of the International Monetary Fund.

They say that her credibility "cannot withstand the most basic evaluation." Their request to drop the case is to go before a judge Tuesday.

Diallo's lawyer, Kenneth Thompson, condemned prosecutors for their handling of the case.

"Manhattan District Attorney Cyrus Vance has denied the right of a woman to get justice in a rape case," he said in a statement. "He has not only turned his back on this innocent victim. But he has also turned his back on the forensic, medical and other physical evidence in this case." 

Strauss-Kahn 'grateful'

Strauss-Kahn's lawyers, William Taylor and Benjamin Brafman, issued a statement saying that the French diplomat and his family were grateful for the decision.

"We have maintained from the beginning of this case that our client is innocent," they said. "We also maintained that there were many reasons to believe that Mr. Strauss-Kahn's accuser was not credible."

The case captured international attention as a seeming cauldron of sex, violence, power and politics: A promising French presidential contender, known in his homeland as "the Great Seducer," accused of a brutal and contemptuous attack on an African immigrant who had come to clean his plush suite at the Sofitel hotel.

The stakes were high for Strauss-Kahn, who resigned his IMF post, spent nearly a week behind bars and then spent possibly hundreds of thousands of dollars to pay for house arrest, as well for Vance, who was handling the biggest case he has had during his 18 months in office.

Strauss-Kahn, 62, was arrested after Diallo, 32, said he chased her down and forced her to perform oral sex. Strauss-Kahn denied the allegations, and his lawyers have said anything that happened wasn't forced.

Like many sexual assault cases, in which the accused and accuser are often the only eyewitnesses, the Strauss-Kahn case has hinged heavily on the woman's believability.

Case began to unravel

Early on, prosecutors stressed that Diallo had provided "a compelling and unwavering story" replete with "very powerful details" and buttressed by forensic evidence; his semen was found on her uniform. The police commissioner said seasoned detectives had found her credible.

But then prosecutors said July 1 they'd found the maid had told them a series of troubling falsehoods, including a persuasive but phony account of having been gang-raped in her native Guinea. She said she was echoing a story she'd told to enhance her 2003 application for political asylum. She told interviewers she was raped in her homeland under other circumstances and embellished it to get herself and her 15-year-old daughter a chance at a better life in the U.S.

'The nature and number of the complainant's falsehoods leave us unable to credit her version of events beyond a reasonable doubt' —New York prosecutors, in a court filing

She also wasn't consistent about what she did after her encounter with Strauss-Kahn, telling a grand jury she had hovered in a hallway when she actually returned to his and another room before consulting her boss, prosecutors said. She said the alleged discrepancy was a misunderstanding.

She also alluded to Strauss-Kahn's wealth in a recorded phone conversation with a jailed friend, and her bank account had been a repository for tens of thousands of dollars she couldn't explain, a law enforcement official has said.

She said a jailed man had used the bank account without telling her. As for the phone call, her lawyer, Kenneth Thompson, said she mentioned Strauss-Kahn's money only to say that her alleged attacker was influential.

Prosecutors said in their filing that without other evidence verifying her claim that Strauss-Kahn attacked her, and sexually assaulted her by force, they weren't willing to base the case entirely on Diallo's truthfulness, when her credibility "cannot withstand the most basic evaluation."

"The nature and number of the complainant's falsehoods leave us unable to credit her version of events beyond a reasonable doubt, whatever the truth may be about the encounter between the complainant and the defendant," they said.

She sued Strauss-Kahn Aug. 8, seeking unspecified damages and promising to air other allegations that Strauss-Kahn accosted and attacked women in other locales.

His lawyers called her suit a meritless claim that proved she was out for money.