High School Musical couple Zac Efron and Vanessa Hudgens have shocked their young fans - after appearing together in a series of saucy beach snaps.

In the paparazzi pictures, published in U.S. magazine In Touch Weekly, the Disney stars can be seen embracing one another while vacationing in the Turks and Caicos Islands over the 4th of July weekend.

And in one especially risque photo, Hudgens straddles Efron while wearing a bright red string bikini.

Last year, 19-year-old Hudgens was devastated when full-frontal nude shots, allegedly taken to titillate Efron, appeared on the internet.