Dominique Strauss-Kahn is to be questioned next week by police investigating an alleged prostitution ring in northern France, officials say.
Mr Strauss-Kahn has been summoned for questioning on Tuesday and can be held for up to 48 hours without charge.
He resigned from the International Monetary Fund last May when charged with raping a New York hotel maid.
Although the case was later dropped, it ended his ambitions to run for the French presidency.
A French inquiry into attempted rape claims brought by writer Tristane Banon against Mr Strauss-Kahn was also dropped.
But he still faces a civil suit in the US by his alleged victim in New York, Nafissatou Diallo. Mr Strauss-Kahn has always denied any wrongdoing.
'Carlton affair'
The latest scandal involves an alleged prostitution ring and the organisation of sex parties at luxury hotels in the city of Lille.
Consorting with prostitutes is legal in France but supplying prostitutes to others is illegal. It is also illegal for an official to accept gifts of any kind from a company.
Reports say Mr Strauss-Kahn could be charged if magistrates deem that he was aware the women who took part in sex parties he is alleged to have attended were prostitutes.
The Reuters news agency reports that Mr Strauss Kahn's lawyer has previously said the former IMF chief thought he was participating in swingers' parties and had no reason to believe the women involved were prostitutes.
The affair has already led to the arrests of several leading figures in the city, including businessmen and police chiefs.
Mr Strauss Kahn has demanded to be questioned by the judges leading the investigation, in the hope it will bring a halt to such newspaper reports and clear his name.
Lawyers for Mr Strauss Kahn have previously said that he will take legal action over his alleged invasion of privacy.
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