The 'Praying' singer is being sued for defamation by the producer - who she has previously accused of abusing her - over her allegations he sexually assaulted her and gave her drugs against her will, and it has now been revealed his third issue stems from a text that Kesha sent to Lady GaGa about the 'Roar' singer.
Court documents obtained by The Blast stated: ''On February 26, 2016 [Kesha] sent a text message to Stefani Germanotta p/k/a/ Lady Gaga which repeated [Kesha's] false claim that [Luke] had raped her.
''[Kesha] also falsely asserted that [Luke] had also raped Kathryn Hudson p/k/a/ Katy Perry.
''Following this text message conversation, and with [Kesha's] encouragement, [Lady Gaga] spread negative messages about [Luke] in the press and on social media.(sic)''
Luke - who has denied the claim - stated the 'Poker Face' hitmaker created ''graphics'' with the help of Kesha to post on social media and referred to the 31-year-old singer's claims of sexual assault by the producer.
The text message was previously discussed by the legal teams of those involved in the case, but its contents had been redacted from documents so no one outside knew what it said.
Katy has never publicly made accusations against the producer - whose real name is Lukasz Gottwald - but has said she separated from him professionally because she had to ''leave the nest''. The documents showed she has given a deposition in the case but its contents weren't disclosed.
Luke - who has claimed he has lost out on millions and believes Kesha's allegations have damaged his reputation and career - has slammed the 'Tik Tok' hitmaker's ''irresponsible'' and ''disrespectful'' claims.
His legal team issued a statement which read: ''Katy Perry herself confirmed that Dr. Luke did not rape her. Kesha's accusation to the contrary -- just like her other outrageous lies about Dr. Luke -- is baseless and irresponsible, and it is disrespectful to both Katy Perry and Dr. Luke. In his defamation lawsuit against Kesha, Dr. Luke seeks damages for the harm caused by these malicious falsehoods.''