Andy Serkis needed a physiotherapist to make sure his body didn't seize up during his physical portrayal of movie monster King Kong.

The British star, who put his body under tremendous strain for hours every day by moving around like a gorilla, had to stay fit because damaging his body would have spelt disaster for the movie.

He says, "My biggest fear was really injuring myself. They couldn't carry on without me. So I was very worried.

"And it was hard to unplug after filming, I was pretty much a vegetable by the end of the day."