Gossip Girl star Ed Westwick has landed a major supporting role in J. Edgar, the Clint Eastwood-directed drama about manipulative FBI director J. Edgar Hoover that stars Leonardo DiCaprio. At the same time, Charlize Theron will not be playing the role of Helen Gandy, as was rumored. She’s signing on for Snow White and the Huntsman at Universal and Eastwood is now looking at Naomi Watts and Amy Adams as possibles for the Gandy role. As for Westwick, the British actor will play a clean cut operative with writing skill. Once Hoover discovers he can write, he conscripts Agent Smith to write Hoover’s biography, until Smith gets a little too close to the truth. The film’s produced by Brian Grazer’s Imagine Entertainment and Eastwood’s Malpaso. The Social Network‘s Armie Hammer also signed on to play Hoover’s assistant and secret lover Clyde Tolson.