Kesha's mother, Rosemary Patricia "Pebe" Sebert, is speaking out about the alleged years of abuse she says her daughter endured from producer Dr. Luke.
"She was a prisoner," Sebert claims to Billboard in a new interview about her 29-year-old daughter's relationship with 42-year-old Dr. Luke. "It was like someone who beats you every day and hangs you from a chain and then comes in and gives you a piece of bread. Luke would say, 'You look nice today,' and send her into hysterics of happiness because she was programmed to expect nothing but abuse."
Kesha sued Dr. Luke -- whose real name is Lukasz Gottwald -- in October 2014, accusing him of drugging and raping her more than a decade earlier, and continuing to abuse her both physically and emotionally from the time she moved to Los Angeles to pursue her career in 2005. Dr. Luke has denied all wrongdoing, and filed a countersuit accusing Kesha of attempting to "extort" him into releasing her from her contract.
WATCH: Kesha vs. Dr. Luke -- Everything You Need to Know About the Ongoing Legal Drama
On Wednesday, Dr. Luke denied a report from The Wrap claiming that Sony Music is preparing to drop him from its roster amid legal turmoil involving Kesha.
"I wanted Kesha to come forward a long time ago and end this relationship with Dr. Luke immediately after the [alleged] rape," Sebert says. "But if she wanted to have a shot at the music business, she had no choice but [to work with him]."
Sebert also says she regrets not going to the police after she claims Dr. Luke drugged and raped Kesha in his hotel room following a 2005 birthday party for Nicky Hilton at her sister Paris' Hollywood Hills mansion.
"Kesha told me not to do anything," Sebert says. "She said, 'Mom, I just want to sing. I don't want to be a rape-case victim. I just want to get my music out.' I didn't follow my instincts."
Sebert claims Dr. Luke's relationship with Kesha only got worse when the singer's career hit a breakthrough with her 2009 hit, "Tik Tok."
"This is when Luke started getting really hateful," Sebert alleges. "He saw her as a cash cow and started manipulating her all the time. She thought all her dreams were finally coming true, but this was just a fu**ing trip to hell."
Last month, a New York Supreme Court judge denied Kesha's request to be let out of her contract with Sony Music, citing a lack of evidence to corroborate Kesha's claims of abuse and sexual assault.
Sebert says although her daughter is allowed to work with another producer under her current contract, Dr. Luke would still have plenty of control over Kesha's career.
"Kesha's allowed to work with another producer, but Luke gets to approve them," Sebert claims. "He gets to approve of anyone she works with. He has final say over everything."
At one point, the "Die Young" singer did in fact attempt to sign another record deal with Warner Bros. Records through A&R executive and former American Idol judge, Kara DioGuardi, DioGuardi confirms to Billboard. But after she and Kesha reached a signed agreement, DioGuardi says she was released when Dr. Luke called her to say that he had a pre-existing contract with Kesha.
"Kesha would tell me she was going to take her car to Mulholland and drive off the cliff," Sebert claims about her daughter's state of mind after the failed deal. "She was a little dramatic, but I never knew for sure."
Sebert says her daughter is now in a better place after coming forward with her allegations.
"She wasn't comfortable with having to do this, but I think she realized as this thing progressed that she can advocate for sexual abuse or other things," Sebert says. "The fact that she is at peace with that has really been healing."
Sebert, a songwriter, is also involved in her own legal battle with Dr. Luke, who sued her for defamation after receiving Kesha's lawsuit. The case was dismissed last month, but Dr. Luke subsequently filed a similar suit in Tennessee, where Sebert lives.
Meanwhile, a representative for Sony had no comment when approached by ET on The Wrap's report that Sony Music is preparing to drop Dr. Luke from its roster a year ahead of his contract's expiration.
WATCH: Taylor Swift Supports Kesha by Gifting Her $250,000 Amid Dr. Luke Legal Battle
Kesha has, however, been getting plenty of celebrity support, including from Adele, Taylor Swift, Kelly Clarkson, and Lady Gaga. Clarkson talked about her own experience working with Dr. Luke on two hits -- 2004's "Since U Been Gone" and 2009's "My Life Would Suck Without You" -- in a radio interview earlier this month with Australia's KIIS FM.
"Her situation is very different from mine, apparently. He never did anything like that with me. I don't know that part," Clarkson said. "I can't really say anything other than that… I wasn't there. I don't know specifically what happened in their situation. Obviously, I wasn't in the room."
"But I can remark on his character," she added. "Unfortunately, when you have that poor of character -- like, so many artists don't like you and don't like working with you -- that's not normal. I get along with everybody I work with, I love everyone I work with, and he's just not a good guy for me."