Nafissatou Diallo is bringing the civil case against Strauss-Kahn after an earlier criminal case was dismissed in August by public prosecutors in New York.
Several French newspapers reported on Wednesday that news agency AFP has seen surveillance footage showing Strauss-Kahn entering the Sofitel hotel at around 1am on May 14th this year, just hours before the alleged attack on Diallo.
According to daily newspaper 20 Minutes, a blonde woman carrying a large black bag entered 20 seconds after Strauss-Kahn. She waited while he spoke to the hotel receptionist before they got into the elevator together.
The woman was then seen leaving the hotel just before 4am later that morning.
Lawyers for Diallo said they wanted to find out the identity of the woman.
"Dominique Strauss-Kahn made an effort to hide that they were together," said Douglas Wigdor. "I don't know who this person is, but I will find out during our investigations for the civil case and I will call on her to testify."
The lawyer dismissed a theory that the whole affair may have been a conspiracy designed to destroy Strauss-Kahn's political ambitions as "completely ridiculous." The allegations were made in an article published in the New York Review of Books at the weekend.
Domnique Strauss-Kahn has repeatedly denied that a sexual assault took place and his lawyers have filed a motion for dismissal of the civil case.