Benedict Cumberbatch's performance as Julian Assange has been unveiled in the first trailer for Wikileaks film The Fifth Estate.
The film is a fictionalised account of the Wikileaks saga, starring the Sherlock actor as Assange, the website's founder who leaked confidential information on the US military's operations in Afghanistan and Iraq to newspapers including the Guardian, the New York Times and Der Spiegel.
Cumberbatch makes an extreme transformation for the film, with his face aged with make-up, his hair long and white, and he adopts an Australian accent in his bid to become Assange.
The trailer shows events leading up to Wikileaks major revelations which shook the world.
Cumberbatch appears giving a speech in which Assange declares himself as "one whistle-blower willing to expose secrets and topple the most powerful and most repressive of regimes."
It has been described by Assange as a "massive propaganda attack".
The Fifth Estate is to be released in UK cinemas on January 1, 2014.