Theron, Hammer to join DiCaprio's 'J. Edgar'

Charlize Theron and The Social Network's Armie Hammer will reportedly join the cast of Leonardo DiCaprio's J. Edgar Hoover biopic.

The Clint Eastwood-directed film, titled J. Edgar, tracks the life of the founder and former director of the FBI.

Theron is being eyed for the part of Helen Gandy, a Justice Department clerk who is selected to be Hoover's personal secretary. Hammer, meanwhile, has been approached to play Clyde Tolson, Hoover's protégé and alleged lover. Joaquin Phoenix had previously been linked to the Tolson part.

Eastwood will begin filming on J. Edgar next year from a script by Oscar winner Dustin Lance Black (Milk).