Leonardo DiCaprio, who stars as FBI boss J. Edgar Hoover in the film J. Edgar, has said he's uncertain whether Hoover was gay.

The Clint Eastwood-directed film opened the 25th edition of the AFI Festival in Hollywood, California on Thursday. (A trailer for the film is embedded in the right panel of this page.)

At the premiere, DiCaprio told E! Online that Hoover's sexual orientation remained a mystery to him.

“To tell you the truth, I don't have the answer to that question and I don't think there's anyone still alive who really does,” he answered.

“If you talk to the Federal Bureau of Investigation, there are staunch believers that these two men carried out a very professional relationship and they were sort of inseparable pals,” DiCaprio stated, referring to Clyde Tolson (played by Armie Hammer, The Social Network), Hoover's co-worker, life-long confidant and alleged lover.

“These two men went on every vacation together. They ate breakfast, lunch and dinner together. They went to work together. They were together for 50 years. They lived together. They were buried together. They never had a family. They never had a girlfriend. You know, put it together in your mind …,” he added.

“He could have have been,” Eastwood added.