He camped out in the wilderness, ate road kill and kept his sword close to his hip at all times during the shooting of Lord of the Rings.

But the trilogy's star, Viggo Mortensen, yesterday said reports of his eccentricity were overblown.

"You mean because I worked hard on it?" Mortensen asked.

"I think some of that's exaggerated but the fact is I always work hard and learn until it's all over, until the shoot is completely done.

"You don't have to, but you're going to do a better job the more you inform yourself."

In Melbourne to promote his latest film, A History of Violence, Mortensen made no apologies for recently describing US President George W. Bush as "a beast".

"It's not my goal in life to go and make comments about politics, but...once you know something and you see something that is misleading, that's untrue, that's unfair, harmful to your fellow citizens and the world, it's kind of irresponsible not to say something."

He didn't spare Prime Minister John Howard in his criticism of the war in Iraq.

"There was such an effort to mislead made by Howard, Blair, Bush and lots of other people to justify why they took their countries to war," Mortensen said.

"When you start to realise that these people weren't being truthful, the illusion of being the good guy crumbles."

Mortensen, 47, had been working as an actor for more than 15 years before his role as the man who would be king in Lord of the Rings shot him to fame.