A French senator was in custody Friday on suspicion of drugging an MP with a view to assaulting her, prosecutors and sources familiar with the case told AFP.
Joel Guerriau, a centrist senator from western France, was being held for "administering to a person without their knowledge a substance likely to diminish their judgement or self-control to commit a rape or sexual assault," prosecutors said on Thursday.
While the prosecutors named the victim only as "a woman, who filed a complaint", several sources familiar with the case told AFP she was an MP.
She allegedly felt strange after accepting a drink on Tuesday night at the 66-year-old senator's Paris home.
Prosecutors said the two were not in an intimate relationship.
Tests revealed that she had ecstasy in her system, investigators added, prompting her to file a criminal complaint.
Guerriau was arrested and held in custody under caught-in-the-act rules allowing police to override his parliamentary immunity, prosecutors said.
Broadcaster RMC, which first reported the story, said that police had searched his office and home, where prosecutors confirmed they found ecstasy.
Originally a banker, Guerriau has been a member of the senate since 2011 and is deputy head of the foreign and military affairs committee.
His lawyer, Remi-Pierre Drai, said he was "outraged to see information from the investigation in the press".
"I'm amazed that the victim's name has not been leaked, unlike my client's," he added.