Viggo Mortensen used an unusual lucky charm on the set of new movie A History of Violence - a life-size plastic fish.

The LORD OF THE RINGS star nabbed the anatomically-correct trout from his on-screen daughter, who was given the fish as a toy, and he carried it everywhere he went.

Mortensen explains, "It was a compulsive thing after a while. I felt like it was unlucky not to have the trout, so I would sneak it in. It became this game to see if I could keep getting away with it."

His secret was blown when he accidentally dropped the fish on camera, on the last day of the shoot - in front of director David Cronenberg.

The actor adds, "David was appalled."