Getty/INSIDER Dr. Luke and Kesha in 2011.
In an emotional interview with Billboard, Sebert opened up about her daughter's alleged abuse at the hands of Dr. Luke (real name Lukasz Gottwald).
"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," she told Billboard of the relationship. "Luke would say, 'You look nice today,' and send her into hysterics of happiness because she was programmed to expect nothing but abuse."
Kesha and Dr. Luke have been embroiled in a legal battle since 2014. Kesha is contractually required to release six records under Kemosabe Records, Dr. Luke's label owned by Sony, and is seeking to leave after accusing him of sexual assault.
A New York judge denied Kesha's injunction request in February, which, if granted, would have allowed her to continue making music under another label while the case is ongoing. She hasn't released music since 2013.
Though she is allowed to work with another producer, Dr. Luke must approve the person, Sebert said.
Sebert described an instance of alleged abuse that happened during a party for designer Nicky Hilton on October 5, 2005.
According to Sebert, Dr. Luke drugged Kesha with what he called "sober pills" - actually a drug used in date rapes known as GHB - and raped her in his hotel room.
Sebert said she struggled to get ahold of her daughter the next day, but when she finally did, Kesha said, "Mom, I don't know where I am. I think we had sex. I'm sore and sick. I don't know where my clothes are. I think I need to go to the hospital." Sebert said Kesha's phone then died, a friend picked her up, and she never went to the hospital.
"Looking back, I don't know why we didn't go to the police," Sebert said. "Kesha told me not to do anything. 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 remembered another incident in which Kesha called her mother after Dr. Luke allegedly forced her to snort a drug on an airplane. This incident is mentioned in Kesha's 2014 lawsuit.
"I do remember her calling me from the plane telling me that she was so drunk, and [how] Dr. Luke came over and started making out with her and was all over her," Sebert said. "She told me she felt terrible and was trying to get away from him and then vomited."
Dr. Luke allegedly becamse harsher as Kesha found success. "He saw her as a cash cow and started manipulating her all the time," Sebert said. "She thought all her dreams were finally coming true, but this was just a f---ing trip to hell."
Sebert later added: "Luke almost destroyed us. And he has done it intentionally."