The lawyers quote the IMF and the U.S. Department of State as saying Strauss-Kahn wasn't immune in the days after the May encounter at the Sofitel hotel in Manhattan.
According to the papers filed Monday by attorney Douglas Wigdor, the Department of State wrote: "The IMF is not seeking to assert any immunities on behalf of Dominique Strauss-Kahn. But our understanding is that immunity in this particular case and with IMF officials is that it would only involve their official capacity and carrying out their duties in their official role. And that doesn't apply in this case."
Strauss-Kahn initially was charged with attempted rape after the maid said he attacked her in his hotel suite and forced her to perform oral sex. The criminal case was dismissed when prosecutors said they had lost faith in her credibility after a series of lies she told them unrelated to the assault allegations.
The maid filed the civil complaint against the one-time French presidential contender when the criminal case was still active.
Strauss-Kahn argued last month that the civil case, pending in the Bronx, should be dismissed because he had diplomatic immunity.
His lawyers argued he should be immune under international law even though he had already resigned his post as leader of the IMF when the lawsuit was filed. They said his immunity stood until he left the United States, shortly after his criminal case was dismissed.
Attorneys for the maid, Guinean immigrant Nafissatou Diallo, said the suggestion Strauss-Kahn had immunity was "a transparent attempt to delay these proceedings and should be denied in its entirety as utterly meritless and frivolous." If he had any immunity at all, they argued, he forfeited it when he resigned.
An IMF quote on the issue echoed the Department of State, saying his immunities were limited and not applicable to this case.
Attorneys for Diallo, who came forward publicly in a series of interviews, filed the lawsuit against Strauss-Kahn on Aug. 8. The motion filed Monday reiterated in graphic detail her version of their encounter. The lawsuit doesn't ask for specific damages.
There is a lower burden of proof in civil cases, and it is possible that Strauss-Kahn would have to testify if the maid's case went to trial.
Strauss-Kahn, who's married, has admitted what he called an inappropriate sexual encounter with the chambermaid, calling it a "moral failing" that he deeply regrets but insisting there was no violence.
A writer's case against Strauss-Kahn in Paris also was dropped this month. French prosecutors said that while he may have done something that qualifies as sexual assault they couldn't send him to trial because it happened too long ago. Strauss-Kahn called the writer's claim imaginary.