PROSECUTORS in the Dominique Strauss- Kahn case remain convinced they have solid evidence of a sexual encounter with a luxury hotel maid but, despite having spent extensive time investigating whether the victim was engaged in a financial extortion plot, they have yet to find any substantive proof, according to people familiar with the investigation.

Investigators began exploring whether the victim had financial motives long before stories surfaced in recent days suggesting she might have been a gold-digger – even a prostitute – who staged the encounter, sources told The Daily Beast.

While the investigative efforts uncovered a trail of previously unknown phones tied to the alleged victim as well as suspicious financial transactions, and even a prison call with a drug suspect in which the idea of financial gain was discussed, no evidence has been found to suggest premeditated extortion, sources said, speaking on condition of anonymity.

Investigators “began looking at that some time ago and don’t see that here so far,” said one source.

“Whenever you have a very wealthy defendant who is being accused of a sex crime, you begin looking at everything, including did money change hands between the victim and the defendant when [the sexual encounter] happened? Or was someone paid to make it happen?” Prosecutors also have testimony from hotel colleagues that bolster the maid’s contention that she believed Strauss-Kahn had already left his hotel suite when she entered to clean the room moments before the alleged incident — undercutting the suggestion of a premeditated plot, the sources said.

Nonetheless, prosecutors are now deeply uncertain whether the victim could withstand cross-examination during a high-profile trial after making a series of false claims to them in recent weeks, and recanting an earlier allegation about a rape that supposedly took place in her native Guinea as well as admitting she falsified information on an asylum application.

The prosecution team recognises “a really terrible witness can still be a victim,” but now has to decide in the coming weeks if the maid “is someone we can put on the stand and trust,” one source directly familiar with the case said.

The sources’ description of the current state of play comes as Manhattan District Attorney Cyrus Vance’s office faces questions about whether the DA’s office adequately checked all the evidence or rushed to an indictment too soon.

The Daily Beast has learned that, until last week, investigators didn’t seek electronic keycard evidence for rooms the alleged victim cleaned at the hotel the day of the alleged attack, other than Strauss-Kahn’s.

That omission has taken on new significance as the maid’s account changed.

The maid originally alleged that on May 14, Strauss-Kahn, one of the world’s most powerful men as a leading candidate for president of France and then-director of the International Monetary Fund, exited a shower in his luxury suite at the Sofitel hotel in New York City, grabbed her from behind and sexually assaulted her after she entered to clean his suite.

Bolstered by significant forensic evidence that included Strauss-Kahn’s DNA, prosecutors in the Manhattan district attorney’s office secured an indictment just days after the attack.

But in recent weeks, their case began to unravel as investigators dug deeper into how the maid immigrated to the United States under a political asylum claim that included some false information.

High-powered lawyers for Strauss-Kahn had by then already combed New York's African immigrant world, uncovering their own evidence challenging the alleged victim’s credibility.

As prosecutors’ doubts mounted, the DA’s office last week disclosed to defence lawyers that they believed there were problems with the victim’s testimony and agreed to loosen the terms of Strauss-Kahn’s bail.

Meanwhile, as questions surfaced about her background, the alleged victim began to change her story.

After weeks of offering a consistent narrative about exactly what she had done after fleeing Strauss-Kahn’s room on May 14, she suddenly made some changes to that account, the sources said.

The maid had told her hotel superiors, hotel security, police detectives, prosecutors and the grand jury that, after Strauss-Kahn forced her to have oral sex, she managed to flee his room and hide around the corner where a housekeeping supervisor found her after Strauss-Kahn had left the hotel.

But according to a letter prosecutors placed in the court file on Friday she stated that, after the attack and before the housekeeper found her, she went and cleaned another room.

(John Solomon is the editor of news and investigations for Newsweek and The Daily Beast.)