Kelly Clarkson has reportedly accused Dr Luke of lying in a bid to take sole credit for writing songs that she also worked on.
The American pop star has made the accusation in the testimony she gave in Kesha's legal battle with Dr Luke, according to the The Blast, which reports Kelly believes the record producer lied to Grammy Award-winning music executive Clive Davis.
Recalling a meeting she had about her songwriting exploits, Kelly reportedly said in June 2017: "I was told by my label executive ... it was a really rough meeting, Clive Davis, where first of all, he told me I was a s****y writer and that I shouldn't - I should just shut up and listen to the producers.
"And then he said, and I said or he said something about hits. 'You should just take the hits and just sing them,' or something to that extent.
"And I said, 'Well, I'm a writer on these. I mean, I wrote on 'Miss Independent'. I wrote on like 'Hazel Eyes'. I wrote 'Because Of You' myself. Like I wrote, like I'm like...' and then he proceeded to say that I did not.
"Well, he told me I was lying. That Dr Luke told him that he had written 'Hazel Eyes.' And I was like, I'm pretty sure I went through a real s****y relationship."
Kelly - who has a long-running feud with Clive - reportedly admitted to being hurt by the accusation.
She said: "It's hurtful whenever you try so hard and you have been accomplished in a certain area. And then somebody just lies about their part in a song.
"And I said, 'Well, we definitely did collaborate'. But I can pull out the lyrics from a notebook piece of paper that I still have ... I wasn't there when Dr Luke apparently had a conversation with Clive ... That really frankly p****d me off."