Actor James Franco has apologised to Justin Bieber for mocking the teenage pop star in a spoof online music video.

The Spider-Man star donned a blonde wig and baseball cap as he lip-synced along to the singer's hit track Boyfriend in a viral clip posted on his page earlier this month (08Jan13).

The parody angered many of the 18 year old's loyal fans and it was quickly removed from the photo sharing website, and now Franco has broken his silence about the prank, insisting he didn't mean to offend Bieber and was just having a little fun with the song.

He tells, "I was asked to take it down by some people. Bieber didn't contact me, but I don't think he was too happy. I wasn't trying to diss him."