Dominique Strauss-Kahn has admitted he was morally at fault when he had sex with a hotel maid in New York, but has told French television he did not rape her.
The former head of the International Monetary Fund said he regretted that the affair had lost him his chance to stand for the French presidency in 2012, but denied using violence, the BBC reports.
He said he had been afraid and humiliated by the US justice system.
Mr Strauss-Kahn, 62, resigned as IMF chief after his arrest on 14 May. The maid, Nafissatou Diallo, is bringing a civil suit against him.
Criminal charges were dropped in August when prosecutors said Ms Diallo's lack of credibility meant the case could not continue.
Mr Strauss-Kahn was questioned by Claire Chazal, a friend of his journalist wife Anne Sinclair on the main Sunday night bulletin of TF1.
''What happened was more than an inappropriate relationship. It was an error,'' he said, adding that he regretted it infinitely.
He said the incident had caused him to miss his ''appointment with the French people''.
Before his arrest, Mr Strauss-Kahn was expected to be a strong contender against President Nicolas Sarkozy next year.
However, he said he could "obviously" no longer be a candidate and would play no part in the forthcoming Socialist primaries. He would now "take time to reflect" on his future.
Mr Strauss-Kahn also faces an allegation by author Tristane Banon that he tried to rape her in 2003.
He said that Ms Banon's accusations were imaginary and there was ''no violence''. He is suing for defamation.