Dwayne Johnson is remaining tight-lipped on a possible collaboration with heartthrob Zac Efron.

The ex-wrestler, who used to be known as The Rock, is set to appear in a big-screen adaptation of the animated scif-fi Jonny Quest series.

There are widespread rumous that High School Musical star Efron will appear in the title role despite being ten years older than the character, an 11-year-old who accompanies his father on fantasy adventures.

Johnson said it was far from certain that Efron will team up with him and director Andy Fickman, saying: "I'm not quite sure if that's going to happen. I don't know. We'll have to see."

But he added: "Working with Zac Efron, we've become buddies. I really like Zac. He's a great guy.

"The idea of the three of us working together on something cool, that would be awesome."

© Independent Television News Limited 2009. All rights reserved.