Bieber a 'brat' on CSI set

CSI star Marg Helgenberger was not impressed by Justin Bieber's behaviour when he made a guest appearance on the TV drama, admitting he was "kind of a brat".

The Baby singer signed on to star as troubled teen Jason McCann last year, and producers were so impressed with his acting, they brought his character back for a second episode earlier this year.

But renowned prankster Bieber's cheeky antics off camera did not win him a fan in Helgenberger.

"He never acted before. I mean, I shouldn't be saying this but he was kind of a brat," she said on a French radio show on Friday.

"I only had one (scene with him). He was very nice to me, but he locked one of the producers in the closet, (and) he put his fist through a cake that was on the cafeteria table."

-AAP