Leonardo DiCaprio had to undergo hours in the make-up chair to portray J. Edgar Hoover, the chubby director of America's Federal Bureau of Investigation (FBI), in his new movie because director Clint Eastwood's filming schedule wouldn't allow the star a weight gain break.

The new film chronicles the FBI boss' career over several years, and DiCaprio admits he would have loved to have bulked up his own physique to accurately portray Hoover in his latter years, but he didn't have enough time.

Instead, DiCaprio underwent six hours in hair and make-up, where he was fitted with facial prosthetics to make him look fatter than he is.

He tells Access Hollywood, "I really wanted to take a break and do the whole real physical transformation. Of course, the film wouldn't allow it.

"It was a massive amount of weight to put on in a very short amount of time. So thankfully, I had a lot of people around to help me in that transformation and I think it turned out pretty well."...