The Black Keys have slammed Michael Jackson's posthumous album 'Xscape', calling it ''bullsh*t''.

The 'Fever' hitmakers, who released their new album 'Turn Blue' on Monday (12.05.14), the same day Michael's record came out, aren't impressed by the decision to release the album after his death in 2009.

In the new issue of Rolling Stone magazine, drummer Patrick Carney said: ''[It's] some f**king bulls**t that sucks so bad that it took them three years after he died to make it listenable.

''Like he had to be dead for three years for it to be released.''

Patrick hit out at executive producer La Reid, claiming he only decided to release the album, which was also worked on by Timbaland and Justin Timberlake, because he ''needed a new boat''.

Meanwhile, Patrick also voiced his opinion on pop star Justin Bieber earlier this week, describing him as an ''irresponsible a**hole after a throw away comment to TMZ resulted in Justin telling his fans on Twitter the musician should be ''slapped around''.

He said: ''Justin Bieber, like a f***ing irresponsible a**hole, sicced 40 million Twitter followers on me because I paid him a compliment he didn't understand.

''He shouldn't be f***ing telling his followers to slap me, and then also be doing anti-bullying bullsh*t. It's so irresponsible.

''Honestly, I feel bad for him. Every single person who works with him should f***ing be embarrassed that they don't. . . No one is doing him any favours, you know?

''And honestly, I don't dislike his music. I don't listen to his music, but he needs to not conduct himself that way. Like, really, you make millions of dollars playing music, you should feel f***ing lucky.''