Zac Efron shows off his naughty side by romping in the sand with a nude model in his raunchiest ever photo shoot.

The clean-cut High School Musical heartthrob swaps his boy-next-door image for a more, er, down and dirty look in the sexy shots that see him get to grips with a naked beauty.

In a pose that may shock some of his younger fans, Zac gets rather up close and personal with the model's bare cleavage.

Other pictures show him flaunting his biceps in a dirty t-shirt.

The saucy shoot runs alongside a chat he gave to Interview magazine ahead of the release of his latest movie, 17 Again.

The new issue of Interview hits newsstands March 24.

See more from the shoot below