Dr. Luke: Kesha and Her Mom Tried to Extort Me Over Abuse Allegations

Dr. Luke; Kesha (inset)

Allen Berezovsky/WireImage

By Mia McNiece

10/16/2014 AT 06:40 PM EDT

Dr. Luke is not sitting back quietly after Kesha filed a lawsuit against the powerful music producer claiming he sexually, physically, verbally and emotionally abused her.

"Kesha's lawsuit is a spectacular and outrageous fiction that will go down in flames. As the truth emerges, this sad and misguided smear campaign will only hurt Kesha," Luke's attorney, Christine Lepera, tells PEOPLE in a statement.

"We are confident the courts will decide that Kesha's current claims are absolutely false, chief among them the preposterous accusation that Luke date raped Kesha when she was 18."

Dr. Luke, 41, says the sexual assault lawsuit is part of an extortion plan and that Kesha's mother, Pebe Sebert, sent him an email threatening to go public with the allegations if he refused to release the singer from her contract and give Sebert publishing rights to Kesha's music.

Lepera also claims that in an emailed dated October 29, 2013, Kesha's mother wrote, "Tomorrow I am going to start making public how Dr. Luke blackmailed me into giving him and Circuit publishing credit, on all songs I wrote on warrior, with Kesha and other writers and producers ...We, me and kesha and her friends ... are going to make all of this Really PUBLIC, in the next few days. Luke date raped Kesha when she was 18. Nicky Hilton's birthday? Paris Hilton's house? Luke gave Kesha pills? She ended up naked in his hotel room 2 days later, no longer a virgin? Do we want all this to come out? Either this Luke releases Kesha from all legal contracts, and gives me back all my publishing, or we, Kesha and I. tell the truth. And if I wind up dead, TRUST ME, IT'S IN WRITING TO CALL YOU AND LUKE."

But Kesha's side is not backing down.

"It is telling that Dr. Luke would twist an email from a horrified and justifiably angry mother threatening to tell the truth – the truth! – about the predator that sexually assaulted her daughter," her lawyer, Mark Geragos, tells PEOPLE. "It is offensive – but not surprising – that Dr. Luke would try and pervert the words of a concerned mother to try and keep Kesha under his unilateral control against her will."