PARIS — Investigators have questioned the daughter of Dominique Strauss-Kahn, the former head of the International Monetary Fund, as part of an investigation into accusations that he attempted to rape a young writer, Tristane Banon, in 2003, an official at the prosecutor’s office said on Tuesday.

Camille Strauss-Kahn, Mr. Strauss-Kahn’s youngest child and a Columbia University graduate student, was presumably called to testify before investigators on Monday because she had been a close friend of Ms. Banon in early 2003, at the time the writer said that Mr. Strauss-Kahn tried to rape her during an interview.

On Tuesday, Ms. Banon was quoted by Le Figaro as saying that she had met Ms. Strauss-Kahn after the incident in 2003, to tell her about the attempted rape. Ms. Banon is the goddaughter of Ms. Strauss-Kahn’s mother, Mr. Strauss-Kahn’s former wife.

“I didn’t know how to talk to her,” Ms. Banon was quoted by Le Figaro as saying. “Her father has always been a hero to her.”