Doug Liman has called Sean Penn 'the greatest living actor'
The filmmaker is working with the double Oscar winner on his new movie Fair Game, which sees Penn reunite with his 21 grams co-star Naomi Watts.
Fair Game follows the real life story of Valerie Plame's status as a CIA agent was revealed by White House officials allegedly out to discredit her husband after he wrote a 2003 New York Times op-ed piece saying that the Bush administration had manipulated intelligence about weapons of mass destruction to justify the invasion of Iraq.
In an interview with Digital Spy the filmmaker said: "What's incredible about this movie is that my first two choices to be in the movie were Naomi Watts and Sean Penn.
"Normally you have your first choices only to end up with your third choices and they're great. We actually got our first choices," he said.
"Sean Penn is probably the greatest living actor. I went into the film thinking that and he did not disappoint.
"It's very hard when you have expectations that high. Life must be tough because everyone expects him all the time to be extraordinary, but in reality he just continually is extraordinary."
Liman, who is directing his first movie since Jumper back in 2008, said that Penn became more and more like Joe Wilson the longer that he spent with him.
"He would hang out with Joe Wilson and each day he would become more and more like Joe Wilson. It was like watching a horror movie, Invasion Of The Body Snatchers or something.
"The personality of Joe is being sucked out and going into Sean! It was one of the most magnificent things I've ever seen."
Fair Game premiered at the Cannes Film Festival this week and will be out later this year, is this an early Oscar contender?
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