Justin Bieber's manager Scooter Braun has publicly backed the troubled star following weeks of highly-publicised bad boy antics, insisting the singer's "heart is pure" and he is simply growing up in the public eye.

The Baby hitmaker has been a regular in the headlines amid reports of bad behaviour, including a police investigation over allegations he has been upsetting his neighbours in California and a number of bust-ups with photographers.

More recent rumours suggested Braun has been losing patience with the teenage star, but the manager has now cleared up rumours of a rift between the pair and insisted Bieber's recent troubles are all part of growing up.

In a series of posts on Twitter.com, he writes, "Fact - Justin Bieber's heart is still good and pure and caring. I saw many examples of that tonight. I'm incredibly proud and love that kid... And I have his back forever. Justin Bieber is family and I am proud of him. He is growing and pushing himself as a young man and doing it with the world watching.

"And what he wants is to be good. To be great. And to mean something positive to the world despite the obstacles or the pressures. His heart is pure and I will be right there with him like I promised him 6 years ago. It is all love. How we react to adversity is what defines us as men. Proud of u (sic) Jb. Great talk. Thank u. Love u man!"