(CNN) -- French prosecutors in Lille asked Tuesday for charges to be dropped against former IMF chief Dominique Strauss-Kahn over his alleged participation in a prostitution ring, citing a lack of evidence.
Strauss-Kahn was among a number charged with aggravated pimping in an investigation into sex parties at the Hotel Carlton in the northern city of Lille.
He did not deny attending the parties, his lawyers said, but he did not know that the young women at the parties were being paid for sex. The case is known in France as the "Carlton affair."
A judge will decide whether to act on the recommendations of the office of the Lille prosecutor.
The prosecutor also asked for charges to be dropped against a second man accused in the case, Jean-Luc Vergin, also on the grounds of insufficient evidence.
However, 12 people should be called before the correctional tribunal for acts that will likely be qualified as aggravated pimping, and for a few of them, fraud, abuse of trust and abuse of public funds, a statement from the prosecutor's office said.
Investigating judges filed their 6,800-page dossier with the prosecutor's office in March this year, two years after the investigation was opened by the Lille courthouse into aggravated pimping charges.
Strauss-Khan, a 64-year-old economist, was widely expected to become the Socialist presidential candidate -- until his professional career imploded with an arrest in New York in May 2011.
A New York hotel housekeeper, Nafissatou Diallo, told police that a naked Strauss-Kahn emerged from a room of his spacious luxury hotel suite and tried to force himself on her, at one point dragging her into the bathroom and trying to remove her underwear.
Strauss-Kahn alleged the encounter was consensual, but stepped down from his $500,000 job at the IMF.
A grand jury indicted him on seven counts, including sexual abuse and attempted rape, but prosecutors later dropped the charges after concluding Diallo had lied about some details of the alleged attack -- despite forensic evidence that showed a sexual encounter had occurred.
Diallo then sued Strauss-Kahn. The two sides reached a settlement late last year, the details of which have not been disclosed.
Last October, a French prosecutor dropped an investigation connecting Strauss-Kahn to a possible gang rape in Washington. The young Belgian woman whose testimony was the basis for the inquiry withdrew her previous statement and said she would not press charges, leaving the investigation with no grounds to continue, officials said.
Strauss-Kahn also faced allegations of attempted rape in 2003 against a young French writer, Tristane Banon. But prosecutors said the case could not be pursued because of a statute of limitations.
Strauss-Kahn denied the allegations and has since filed a countersuit in France, alleging slander.
CNN's Alexander Felton contributed to this report.