Zac Efron and Vanessa Hudgens have split, according to sources.

The couple, who met on the set of Disney's High School Musical, have reportedly decided to end their four-year relationship, but friends insist the breakup was amicable.

One told E! Online: "It's nothing dramatic. There's no third party involved."

Another source added: "They are still talking and still friends. There's no drama. No one cheated. They just grew up."

Zac, 23, recently gushed about his relationship with 21-year-old Vanessa but admitted he was pleased they didn't live together as it helped to keep the romance alive.

He said: "When we're filming, we spend a lot of time apart, but that's what keeps it fresh, you know? Also, when you're working, you need to be really focused. At least I like to be focused so that time away is important. Then when you come back, it's better than ever."

He also credited his romance with the brunette beauty for helping him resist the temptations of fame.

He said: "What I will say is that there's lots of drama and distractions and, you know, bulls**t at this age with women that I don't have to put up with. But at the same time, I'm getting to experience the amazingness and the beauty of women. So I'm foregoing all the negative things and really just getting the positive, I think.

"Being in a relationship has definitely helped me stay focused. I think being in a relationship at this point has kept me out of a lot of things that could have distracted me, could have developed into those distractions. And I'm having every bit as much fun."