James Franco poses as Justin Bieber in new spoof

Hollywood actor James Franco has transformed himself into Justin Bieber to mock the teenage pop star in a spoof video.

The Spider-Man star dons a Bieber-style wig and baseball cap as he mimes along to the singer's hit track Boyfriend in a clip posted on celebrity interaction website WhoSay.com.

Franco's rumoured girlfriend Ashley Benson also appears in the video, showing off raunchy dance moves while wearing a brunette wig, apparently in reference to the singer's on/off partner Selena Gomez.

Benson worked with Gomez on new movie Spring Breakers.