Benedict Cumberbatch has signed up to star as a Cold War spy.
Ironbark is based on the true story of Greville Wynne (Cumberbatch), a British businessman who helped penetrate the Soviet nuclear programme.
Wynne and his Russian source, Oleg Penkovsky, provided crucial intelligence that ended the Cuban Missile Crisis.
He spent 18 months in a Moscow prison until he was swapped for a KGB spy arrested in London.
The Hollow Crown and On Chesil Beach filmmaker Dominic Cooke will direct the movie.
Producers Ben Pugh and Rory Aitken said: “Tom O’Connor (writer of The Hitman’s Bodyguard) has written a masterful script, and with Dominic Cooke directing and Benedict Cumberbatch starring, we’re looking forward to collaborating with this uniquely talented team to bring Ironbark to the screen.”
Sherlock actor Cumberbatch is currently starring in Avengers: Infinity War.