US singer Kesha has accused a top music producer of rape, as well as years of sexual, verbal and emotional abuse.
The popstar, famous for hits like Tik Tok, Timber, and Die Young, claims Dr Luke forced her to "take drugs and alcohol in order to take advantage of her sexually while she was intoxicated".
Kesha made the claims against the Grammy Award nominee in a civil suit filed in Los Angeles.
Dr Luke, whose real name is Lukasz Gottwald, hit back with his own legal claim denying the allegations and accusing Kesha and her mother of defamation, breach of contract and contractual interference.
It says the pair have made "false and shocking accusations" to extort him into releasing the 27-year-old from her contract.
"Kesha and her mother are engaged in a campaign of publishing outrageous and untrue statements about Dr Luke to third parties, including scurrilous and false statements of purported physical and mental abuse of Kesha," said Dr Luke's lawyer Christine Lepera.
Dr Luke also produced and co-wrote Miley Cyrus hit Wrecking Ball
Kesha also alleges the producer's insults led to her suffering bulimia. The singer finished two months of treatment for the condition in March.
The lawsuit does not state when the alleged rape happened, but claims the singer did not report it out of fear of retaliation by the producer.
It adds: "She lived in a prison of his abuse and was terrified of speaking, messaging, tweeting or doing anything at all that he might disapprove of in the event that he would later use it to torture her and her family, as he had done so many times before."
Kesha's lawyer, Mark Geragos, added: "This lawsuit is a wholehearted effort by Kesha to regain control of her music career and her personal freedom after suffering for 10 years as a victim of mental manipulation, emotional abuse and sexual assault at the hands of Dr. Luke."
The singer is demanding damages and to escape the contracts she has with Dr Luke, with whom she has been contractually tied since she was 18.
Dr Luke, 41, has worked on a string of hits by the likes of Britney Spears, Katy Perry, Nicki Minaj and Rihanna.
He also produced and co-wrote Miley Cyrus' hit Wrecking Ball.
His lawyer said she was confident Dr Luke would "prevail in all matters, and that our client will be awarded substantial damages for this malicious conduct".