Justin Bieber's former girlfriend claims he "loves weed" and always "has a buzz on".

The 'Believe' hitmaker - who was arrested last week for driving under the influence (DUI), drag racing and resisting arrest - wants to lose his "cheesy" image and be more like his friend and collaborator Lil Wayne, model Milyn Jensen has claimed.

She said: "It's no secret that Justin loves his weed - there's probably not a moment in the day when's he's not got a buzz on.

"He's surrounded himself with the wrong people. He didn't want to be the cheesy popstar anymore and has gone way too far the other way.

"He really looked up to rappers like Lil Wayne. He decided they were cool and who he wanted to be like.

"And it's guys like that who do the stuff that Justin now gets in trouble for."

Milyn - who reportedly had a fling with Justin last year while he was still dating Selena Gomez - believes the 19-year-old singer's pals, including Lil Za and Lil Twist, are leading him astray and letting him deal with his "insecurity" and struggles with global stardom in the wrong way.

She added to The Sun newspaper: "They are the bad influence. They took advantage of his desperation to shed his 'cheesy pop star' image.

"I've been friends with these guys for a long time. When I ask them how Justin is they always say he's fine, he just gets down about all the attention. I think he uses weed as an escape.

"In real life he's actually very shy and insecure. He doesn't act cocky or rude like people would assume. He's just a genuine guy but he needs an escape and he's chosen the wrong way to feel trouble-free."

The brunette beauty is hopeful Justin - who is currently in Panama where his manager Scooter Braun and mentor Usher are believed to be trying to persuade him to check into rehab - can get his life back on track.

She said: "It's worrying. I hope he turns it around."