Naomi Watts has signed on to replace Charlize Theron in the J Edgar Hoover biopic being helmed by Clint Eastwood. 

Leonardo DiCaprio is starring as Hoover in the film, with breakout star of The Social Network, Armie Hammer playing his rumoured gay lover. According to Variety, Watts will play Hoover’s loyal secretary of 54 years, Helen Gandy. She apparently had loads of dirt on the former FBI boss, but kept stum.

Josh Lucas also recently joined the cast as "aviator" Charles Lindbergh.