Justin Bieber has won plaudits for his remarkably grown-up attitude to super stardom.
But while the teenager has so far avoided any scandals, he has been revealed as a 'bit of a brat' by one of the lead star's of CSI.
'I shouldn’t be saying this but he was kind of a brat,' Marg Helgenberger said.
'He was very nice to me. But he locked one of the producers in a closet and he put his fist through a cake that was on the cast’s table.'
Brat: Justin Bieber poses with Marg Helgenberger on the set of CSI; she has revealed that he locked a producer in a closet and put his fist through a cake
Helgenberger, 52, plays CSI investigator Catherine Willows and has received Emmy and Golden Globe nominations for her role.
In the interview, with a French reporter from Europe1, she is seen rolling her eyes when asked if Bieber's role was just to boost ratings or if he was a talented actor.
Helgenberger visibly rolled her eyes when asked if his role was written to raise ratings, or because the singer is 'truly a good actor.'
'Justin Bieber wasn’t bad bad,' Helgenberger said. 'But he’d never acted before... He’s better than you’d think.'
Acting: Bieber had never acted before he took the cameo role in CSI
Helgenberger's criticism is very different to the official line on Bieber.
‘He did a really good job,’ CSI's executive producer Carol Mendelsohn told USA Today earlier this year.
Bieber, 17, played troubled teen Jason McCann in two episodes of the show, broadcast earlier this year.
The character was a member of an anti-government family whose foster dad was in jail and whose brother was out for revenge against the police.
The second episode ended with Bieber's character being gunned down in a stand-off with police.
Bieber said at the time that he was excited about the role.
'It was really cool because I actually - I get shot, like several times,' he said.
'I fall down and there's fake blood and everything. It's crazy how the whole process is.'
Read more: 'He was kind of a brat': CSI star Marg Helgenberger on Justin Bieber's annoying behaviour | Mail Online