The Informant! (2009)

Mark Whitacre has worked for lysine developing company ADM for many years and has even found his way into upper management. But nothing has prepared him for the job he is about to undertake - being a spy for the FBI. Unwillingly pressured into working as an informant against the illegal price-fixing activities of his company, Whitacre gradually adopts the idea that he's a true secret agent.

But as his incessant lies keep piling up, his world begins crashing down around him.