The complaint was filed by a young woman on Thursday, according to The Irish Times.
The prosecutor’s office in Bastia said in a statement that “following a complaint lodged on September 10th denouncing events which might be qualified as attempted sexual aggression and sexual exhibition, Mr Conor Anthony McGregor has been questioned by the gendarmerie, in detention".
Mr McGregor’s Corsican lawyer, Emmanuelle Ramond, said the alleged events referred to occurred on the night of September 6th to 7th.
Ms Ramond told The Irish Times that Mr McGregor was released before the end of his detention period, was not charged and is free to travel.
“In my opinion the complaint was unfounded,” she said, adding that her client “vigorously denies the accusation of misbehaviour".
Mr McGregor, 32, has been vacationing in the region on a yacht with his fiancee, Dee Devlin, and their two children.
He was due to take part in a 180km water bike voyage to raise awareness for water safety.
Mr McGregor was due to start the event yesterday with Princess Charlene of Monaco but he was not listed in the participants for 'Team Notorious'.
