Katy Perry reportedly will amp her feud with Taylor Swift by releasing a diss song against Calvin Harris' girlfriend.

According to the report from The Sun, as shared by Hollywood Life, the title of Katy Perry's song would be "Crocodile Tears" and John Mayer's girlfriend will collaborate with DJ Diplo for the track.

The source alleged, "Katy knew Diplo would be just the man to produce "Crocodile Tears" for her and has now registered it. So far she's been very restrained with what she's said about Taylor in public but is now ready to put her side across via the song - which is all about being fake."

It's been reported that "Bad Blood" is a diss song by Taylor Swift meant to Katy Perry as part of their long-running feud. In the music video, Selena Gomez-who plays the villain-might be channeling the "Fireworks" singer as Justin Bieber's ex is even donning a wig.

As for Katy Perry's diss song for Taylor Swift, the source claimed, "It isn't yet known whether it would be released as a one-off or as part of Katy's fourth album, but she is keen for fans to hear it."

Taylor Swift and Katy Perry's feud has been brewing for a long time.

In her Rolling Stone interview, Taylor Swift might have alluded to Katy Perry when she said, "For years, I was never sure if we were friends or not."

"She would come up to me at awards shows and say something and walk away, and I would think, 'Are we friends, or did she just give me the harshest insult of my life?'"

Their alleged feud came to a head when Katy Perry allegedly stole Taylor Swift's backup dancers, whom people recognized dressed in shark costume during the "Fireworks" singer's performance on Super Bowl.

Taylor Swift confirmed that Katy Perry "tried to sabotage an entire arena tour. She tried to hire a bunch of people out from under me."