BURBANK, Calif. (AP) -- The Leonardo DiCaprio sitting inside an empty soundstage on the Warner Bros. lot on a sunny November afternoon looks very little like J. Edgar Hoover — his title role in Clint Eastwood's new biopic of the longtime FBI director.
On this day, DiCaprio looks relaxed and comfortable, lean and handsome. In "J. Edgar," he's anything but.
DiCaprio portrays Hoover throughout his nearly 50-year reign over the Federal Bureau of Investigation. To play the elder Hoover, the actor endured grueling six-hour makeup sessions that left him unrecognizable even to his director.
"I had a lot of weight on me, too," DiCaprio said. "I kept adding this weight just because I wanted to feel the weight of the country and the world on his shoulders. I just kept feeling more and more claustrophobic, and I tried to use that for the character, because I felt like he felt more and more claustrophobic in his position: He was losing the power that he once had, he was being criticized more than ever and he tried to retain his staunch beliefs of the morals this country should live by."
Eastwood's portrait of Hoover, from a script by Oscar winner Dustin Lance Black ("Milk"), follows the intensely private man throughout his career, from 1919 until his death in 1972. Hoover tells his own story for much of the film, which explores his relationships with the very few people he trusted: His mother (played by Judi Dench); his secretary, Helen Gandy (Naomi Watts); and his associate and companion, Clyde Tolson (Armie Hammer).
It's the depiction of the relationship between Hoover and Tolson that raised the hackles of historians and FBI officials when Eastwood and DiCaprio approached them during their research for the film. Officials maintain that the two men shared a brotherly relationship. The film suggests that perhaps it was more than that.
"My answer is: No one has the real answer," DiCaprio said. "What we're trying to portray here is a partnership, a lifelong partnership that these two men had, and if there was a feeling of love there, I think we accurately portrayed that it was suppressed."
The 37-year-old actor found this story of Hoover so compelling because "the character made me have a million more questions."
"I just wanted to know everything there was to Hoover," he said. "He'd always been shrouded in so much mystery, from his personal life to his politics to his tactics to his highly controversial means of manipulating people politically. I wanted to know more about him, and this script for the first time answered a lot of questions I had about him and shaped a fundamentally interesting character."
DiCaprio delved into his research about the nation's top special agent. He visited Hoover's hometown and toured the house where he died, taking notes about the car he drove and the route he took to work. He visited Hoover's office, talked with FBI officials and spent time with retired agent Deke DeLoach, who worked with Hoover personally. He scoured old photographs and YouTube videos for insight into the always guarded G-Man.
Eastwood called DiCaprio "a total professional."
"He comes prepared," he said. "From the start, I could see he'd done all of his homework, thought a lot about what he had to do, and was interested in my take on things. I was really impressed by his focus, and I think it translated into the character."
Playing Hoover through so many decades over the quick month-and-a-half-lon g shoot was "very difficult to do," the actor said. "The last two weeks were the heavy makeup stuff ... and trying to retain the same character from the earlier film, and add 50 years of experience to him, and the prosthetics slowing your movements down and still having that cadence, it was very stressful."
DiCaprio has played American figures before, including charming con-man Frank Abagnale, Jr. in "Catch Me if You Can" and reclusive eccentric Howard Hughes in "The Aviator," but Hoover, he said, "was a real grab-bag of eccentricities."
"There was so much stuff to work with, but more than anything, I just liked the idea of this element of a man that didn't have any kind of personal life," DiCaprio said. "He got to enjoy himself, go to the track, go on vacations, but his whole life was about infiltrating other people's secrets but repressing his own and attacking anyone who ever tried to reveal anything about his own life. It's a pretty stressful existence."
DiCaprio's own existence is a bit stressful at the moment, too. He's filming "The Great Gatsby" in Australia with Baz Luhrmann and flew to Los Angeles and New York for a few days to promote "J. Edgar" before heading back down under.
"I don't even know what time zone I'm in," he said.
He's enjoying the work on "Gatsby," his first experience with a 3-D film. Luhrmann is using the medium to replicate the experience of watching live theater, DiCaprio said. (Actually, DiCaprio's first experience with 3-D was 1997's "Titanic." He just didn't know it at the time. James Cameron's 3-D conversion is due out in April).
DiCaprio also continues to enjoy his environmental work, a cause he's been committed to for more than a decade. He wrote and produced the 2007 environmental documentary "The 11th Hour" and is working with the World Wildlife Federation's Save Tigers Now campaign. He uses his website and Twitter page to promote ecological efforts and plans to do more, including turning his site into a sort of a virtual soapbox.
"It's a much different era than this movie, that's for sure," he said. "There are no more secrets anymore."