Rockers Crystal Castles have launched a furious tirade against Katy Perry, branding the pop star "evil" and accusing her of "selling sex" to children.

The dance duo is astonished at some of Perry's risque concert routines and tour merchandise, and has slammed her for wearing her notorious 'cream-shooting' bra.

They are adamant the I Kissed a Girl hitmaker should be more responsible around her young audience and blame her for "sexualising" youngsters.

Singer Alice Glass tells NME magazine, "I think a lot of (pop stars) sell sex to children. I think a lot of kids are more sexualised now than they were years ago and I'm not sure it's a coincidence. Like f**king Katy Perry spraying people with her f**king d**k, her f**king c** gun c**ming on f**king children. And little girls, like six-year-old girls wearing a shirt with 'I wanna see your (pea) cock' on it."

Keyboard player/producer Ethan Kath says, "On the merch (merchandise) for that (Perry) song Peacock, the 'Pea' is on a different line so you don't see it. She sells it to f**king children."

Glass adds, "It's f**king evil. Don't prey on vulnerable people like that. Don't encourage little girls to get dressed up, to have cupcakes on their t**s to get people to lick them off, 'cos that's what you're insinuating."