Actor Leonardo DiCaprio has announced the filming start of J. Edgar.

The 36-year-old DiCaprio will play opposite Armie Hammer, the 24-year-old star of The Social Network, in the upcoming biopic of FBI director J. Edgar Hoover.

DiCaprio tweeted to his more than 650,000 followers on Friday: “Start shooting J. Edgar Hoover story on Feb. 5th, look forward to working on more eco projects this year too.”

DiCaprio will play Hoover, while Hammer takes on the role of Clyde Tolson, Hoover's alleged lover.

The film is based on a script by Milk scribe Dustin Lance Black and will be directed by legendary actor-director Clint Eastwood.

Eastwood recently said DiCaprio “volunteered” for the lead role.

“The script is a very good script and we were all preparing it and he [DiCaprio] liked the script,” Eastwood told John Meneghetti on the red carpet for this year's California Hall of Fame induction ceremony. “He actually volunteered for it.”

While there is ample evidence to suggest that Hoover and Tolson were gay and involved in a romantic relationship, both men vehemently denied such allegations.