The case throws up a new headache for the Frenchman, who is in New York fighting sex assault charges that brought his career at the IMF crashing to an end and have likely killed his chances of running for French president next year.
Strauss-Kahn is expected to counter claim against Banon — a routine procedure in such a case in France. His lawyers declined to comment last night.
Banon, 32, filed her complaint earlier this week over an incident she alleges occurred in 2003 when she went to interview the former French finance minister in an otherwise empty Paris apartment when she was in her early twenties.
Her lawyer David Koubbi said there was “physical” evidence to back up the case, although he declined to say if that included text messages or recordings.
Strauss-Kahn had been the favourite to unseat conservative President Nicolas Sarkozy by running for the Socialist Party in France’s 2012 election until his arrest in New York in May threw his political future into question.
That case appeared to weaken last week when prosecutors said they had doubts about the credibility of the hotel chambermaid who has alleged Strauss-Kahn tried to rape her when she went in to clean his room.
A court released Strauss-Kahn from house arrest and signs that the case may be unravelling raised the prospect that he could return to France in the months ahead and take a role supporting the left’s election campaign.
Yet a person close to the case said US prosecutors have no current plans to drop the charges and want at least two or three more weeks to investigate Strauss-Kahn, 62, and his 32-year-old accuser. The source also said that no plea deal was sought in a meeting this week with Strauss-Kahn’s lawyers.
Strauss-Kahn’s arrest in New York sent shockwaves around the world and threw the French left into turmoil as it scrambled to come up with a Plan B strategy for winning the presidency after three terms in opposition.
The scandal has also set off a wave of soul-searching in France, where the media has kept quiet for years about a culture of flirting and extramarital affairs in political circles that critics say risks letting sexual predators go unnoticed.
Banon is a journalist and author of three books, including a novel that gives a fictionalised account of the alleged incident with Strauss-Kahn. She also gave a graphic account of the alleged assault in a televised talk show in 2007 with his name bleeped out, but had never taken legal action until this week.
Attempted rape carries a penalty of up to 15 years in France.
For Banon’s case to stand up, it would need evidence of attempted rape rather than just sexual assault, given that in France attempted rape charges can be brought as long as 10 years after the event but assault charges expire after three years.
While Strauss-Kahn’s allies have rallied round him from the day of his arrest, French voters no longer see him as presidential material — even if many have decried the way he was paraded in front of US cameras unshaven and handcuffed.
An opinion poll carried out in the wake of Banon’s complaint this week found two thirds of respondents did not want Strauss-Kahn to be a candidate in the 2012 election and an even larger share did not believe he would now run.