Oliver Stone's latest controversial biopic will premiere at the BFI London Film Festival today.
Snowden stars Joseph Gordon-Levitt in the titular role as hacker Edward Snowden and the film opens with him in a hotel room in Hong Kong about to blow the whistle on covert surveillance programmes run by the NSA and other intelligence agencies.
Melissa Leo stars opposite Gordon-Levitt as Laura Poitras, the director of the Oscar-winning documentary about Snowden, Citizenfour, while Star Trek actor Zachary Quinto plays journalist Glenn Greenwald.
Joely Richardson, Nicholas Cage, Rhys Ifans and Tom Wilkinson also star in the film, which charts Snowden's rise as an intelligence operative and his romantic relationship with Lindsay Mills, played by Divergent star Shailene Woodley.
Stone and Richardson are both expected at the red carpet premiere at the Odeon Leicester Square.
Leonardo DiCaprio will also be at the festival today for the premiere of his environmental documentary Before The Flood and 12 Years A Slave director Steve McQueen will be honoured with the Fellowship Award when the BFI London Film Festival Awards are handed out at a ceremony at Banqueting House.