Diplo thinks Justin Bieber is a ''jerk''.

The pair recently collaborated on hit single 'Where Are Ü Now' and while they got on well in the studio he admitted he doesn't think the 21-year-old star is always the nicest of characters.

He explained: ''Bieber's personal life is whatever it is -- he's a rich kid and he's pretty much gonna have to be a jerk. But he's respectful to me, and he has that weird gene where he's good at everything: better at basketball than me, better at drums. For us it's more like an art project where you utilize his voice.''

Although the 36-year-old producer and DJ made a mainstream song with the 'Boyfriend' hitmaker, he went on to reveal he has been working on a more rockier sound recently with Vampire Weekend frontman Ezra Koenig and has been ''harassing Haim'' because he's so keen to collaborate with them.

He told Rolling Stone magazine: ''I've done a lot of songs with Ezra Koenig, some really cool stuff that I hope people get to hear. We wrote a couple of things for another artist that might be huge records for the end of summer -- one of them started with a Vampire Weekend idea. But he's not traditional rock -- he's like me, a hodgepodge of styles and influences. And I have a studio with [producer] Ariel Rechtshaid, so every day I'm harassing Haim to listen to my beats. But I don't make anything that they ever like [laughs]!''