One Direction have been in the studio with Justin Bieber, it has emerged.

Boyband star Niall Horan tweeted this morning (April 5) that he was in the studio with Bieber "last night" - and that it is going to sound "great".

What "it" is however is remains somewhat unclear - whether it be the two camps collaborating or just the One Direction boys listening to Bieber's new album. Horan had tweeted:

"In the studio with our boy @justinbieber last night , its gona sound great!"

Horan's bandmate Liam Payne meanwhile had earlier tweeted:

"Got a first listen to justin biebers new album yesterday wowww big songs!!! Its gunna be a smash... Expect the unexpected :o"

To which Bieber replied: "Thanks buddy. good chillin with u guys."