Hollywood actor Val Kilmer is so convincing as '70s porn star JOHN HOLMES - he's petrified his co-stars.

Kilmer takes on the lead role in Wonderland, a dark drama of sex and murder.

And TIM BLAKE-NELSON, who appears alongside him in the flick, admits Kilmer's likeness for Holmes and his method acting have created tension on-set.

He says, "This will restore faith in those who didn't believe that Val Kilmer is one of our best film actors working today."

But Kilmer's method of immersing himself into the characters he plays did add a feeling of discomfort for his colleagues.

Nelson continues, "There were moments working with Val when I didn't know what was going to happen next.

"You felt almost in danger. There was an intensity on that set like I've never experienced before. It wasn't always enjoyable."

The movie, set in the early '80s, is set to hit screens in August (03).