Islamic scholar Tariq Ramadan was charged with rape on Saturday, a judicial source said, following claims by two women that he assaulted them in French hotel rooms in 2009 and 2012.
Ramadan, who was arrested by French police on Wednesday, has now been charged with connected charges of rape and rape of a vulnerable person, the source said.
The accused is a Swiss citizen whose grandfather founded Egypt's Muslim Brotherhood movement.
After two days of questioning by investigators, the 55- year-old Oxford professor was brought before three magistrates who have been assigned to the case, suggesting that he is facing an extensive investigation, judicial sources said.
Women who have testified anonymously during three months of preliminary investigations might now also file rape complaints, one of the sources said.
The claims against the prominent scholar, which emerged in the wake of the Harvey Weinstein scandal in the United States, have divided many Muslims, with his legions of fans, as well as his lawyers, saying he is the victim of a smear campaign.
But critics have long suggested that despite Ramadan's moderate tone as a familiar face on television programmes, he preaches a more radical line when addressing Muslims in Arabic.
Ramadan is the most high-profile figure to be held in France over the sexual assault and harassment claims that have rippled around the world as a result of the "Me Too" campaign.
The married father of four has denied the separate accusations from the two women.
The first was made by Henda Ayari, a feminist activist who previously practised a conservative strain of Islam. She had described being raped in a book published in 2016, without naming her attacker.
But in October, she said she had decided to name Ramadan publicly as the alleged perpetrator as a result of the "Me Too" campaign, using the French hashtag "Balance Ton Porc" (Expose your pig).
She said Ramadan raped her in his hotel room, telling Le Parisien newspaper: "He choked me so hard that I thought I was going to die."
She lodged a rape complaint against Ramadan on October 20.
Several days later an unidentified disabled woman, a Muslim convert, also accused the academic of violently raping her in a hotel room in the southeastern city of Lyon in 2009.
Vanity Fair magazine, which met the woman, said her lawsuit against Ramadan described "blows to the face and body, forced sodomy, rape with an object and various humiliations, including being dragged by the hair to the bathtub and urinated on".
During three hours of testimony in Paris on Thursday, the woman -- using the pseudonym "Christelle" -- recounted her allegations to the judge in Ramadan's presence.