Sean Combs, the producer and music mogul who has been one of the most famous names in hip-hop for decades, was sued in federal court on Thursday by Cassie, an R&B singer once signed to his label, who accused Mr. Combs of rape, and of repeated physical abuse over about a decade.

In the suit, filed in Federal District Court in Manhattan, Cassie, whose real name is Casandra Ventura — and who had long been Mr. Combs’s romantic partner — says that not long after she met him in 2005, when she was 19, he began a pattern of control and abuse that included plying her with drugs, beating her and forcing her to have sex with a succession of male prostitutes while he filmed the encounters. In 2018, the suit says, near the end of their relationship, Mr. Combs forced his way into her home and raped her.

“After years in silence and darkness,” Ms. Ventura said in a statement, “I am finally ready to tell my story, and to speak up on behalf of myself and for the benefit of other women who face violence and abuse in their relationships.”

In response, a lawyer for Mr. Combs, Ben Brafman, said: “Mr. Combs vehemently denies these offensive and outrageous allegations. For the past six months, Mr. Combs has been subjected to Ms. Ventura’s persistent demand of $30 million, under the threat of writing a damaging book about their relationship, which was unequivocally rejected as blatant blackmail. Despite withdrawing her initial threat, Ms. Ventura has now resorted to filing a lawsuit riddled with baseless and outrageous lies, aiming to tarnish Mr. Combs’s reputation and seeking a payday.”

Douglas Wigdor, a lawyer for Ms. Ventura, said the parties had spoken before the suit was filed. “Mr. Combs offered Ms. Ventura eight figures to silence her and prevent the filing of this lawsuit,” he said. “She rejected his efforts.”

Ms. Ventura’s case is the latest in a series of sexual assault civil suits filed recently against prominent men in the music industry, including Steven Tyler of Aerosmith, the executive L.A. Reid and Neil Portnow, the former head of the organization behind the Grammy Awards. (Mr. Portnow has denied the accusation; Mr. Tyler and Mr. Reid have not responded.)