In an interview broadcast Wednesday, Adji Sarr said opposition leader Ousmane Sonko had forced her to sleep with him on several occasions and had threatened reprisals if she refused.
“If Ousmane Sonko has never slept with me, let him swear on the Koran,” said the young woman, in the interview carried by several private television channels in the West African state.
Sarr added that she had fallen pregnant by Sonko.
Police detained the opposition leader — a devout Muslim popular with Senegalese youths — on charges of public disorder after scuffles with his supporters broke out as he travelled to court.
He had been due to appear before a judge in relation to Sarr’s separate rape charge, which she had filed in February.
At least five people died in the clashes between opposition supporters and security forces that followed Sonko’s arrest.
But the judge also formally charged him with rape, paving the way for an investigation.
To many opposition supporters, Sonko’s legal troubles fit a perceived pattern of politically motivated court cases against rivals of President Macky Sall.
Sarr said Wednesday she had never met the president.