Pop singer Kesha has filed a lawsuit against music producer Dr. Luke accusing him of sexual assault and forced use of drugs, reports People.

Kesha, who has been working with Lukasz "Dr. Luke" Gottwald since she was 18, claimed in a document obtained by TMZ that the producer "made repeated sexual advances toward her." She was also allegedly forced to use drugs and alcohol.

The singer cited an instance when the producer forced her to drink with him and gave her a date-rape drug. She claimed she woke up naked in Gottwald's bed, feeling sore, with no recollection of what had happened.

She "immediately called her mother and made a 'fresh complaint," according to the document, but was allegedly threatened by Gottwald to keep the incident a secret.

Kesha, whose real name is Kesha Rose Sebert, also claimed that Gottwald would heavily criticize her for her appearance, saying "you are not that pretty and you are not talented, you are just lucky to have me." She claimed the verbal abuse caused her to have an eating disorder, which she went to rehab for in January.

Kesha's lawyer Mark Geragos released a statement after filing the lawsuit, saying: "The facts presented in our lawsuit paint a picture of a man who is controlling and willing to commit horrible acts of abuse in an attempt to intimidate and impressionable, talented, young female artist into submission for his personal gain."

Gottwald responded to the allegations Tuesday by filing a lawsuit against Kesha, her mother Pebe and her new management company Vector Management for breach of contract and defamation.

"The complaint explains that Kesha and her mother Pebe have wielded these defamatory statements in an attempt to extort Gottwald into releasing Kesha from her exclusive recording agreement with Dr. Luke," said a statement from Gottwald's lawyer Christine Leperea via E! News.

"We understand that Kesha has filed a lawsuit of her own against Dr. Luke, though we have not yet seen it. Undoubtedly, Kesha's lawsuit is nothing more than a continuation of her bad and offensive acts."