Viggo Mortensen believes an actor's performance can be ruined by editing.

The A Dangerous Method actor revealed he was shocked when watching a film he had made to find that the director had cut his lines and put in a whole new sentence by putting together words he had said in other scenes.

''A director decided he didn't like me saying what he had shot and took words I'd said on other scenes and cobbled a new sentence together. I was stunned.''

Filmmaker David Cronenberg who has worked with Viggo on three movies, crime thrillers A History of Violence and Eastern Promises and most recently A Dangerous Method, admitted directors do have the power to completely change an actor's performance in the editing suite: "I spend weeks with the actor in the editing room, looking at every nuance. Even the rhythm of their breathing as they speak. It can really reshape a performance. You hear people say, 'My performance was destroyed in the editing room' It can actually happen."