Issues Julia Michaels Download 'Issues' on iTunes
Katy Perry is 'still friends' with Dr Luke in spite of rumours to the contrary.
A source told Page Six: 'She got tired of his records, the same familar sound, but mostly his attitude. Katy's a star now and she's not going to be told what to do.'
However Dr Luke's spokesperson has called the claims 'ridiculous'.
They said: 'They just put the finishing touches on Katy's newest single, which they created together in February.
'They had a great time and the single is amazing. He wishes Katy nothing but continued success and looks forward to working with her again soon.'