Cillian Murphy will star as J. Robert Oppenheimer in Christopher Nolan's upcoming film about the theoretical physicist.

The 45-year-old actor will once again join forces with his 'Inception' and 'Dunkirk' director for 'Oppenheimer', which has been set for release on July 21, 2023, according to Universal Pictures and Nolan’s banner Syncopy.

The move to Universal is significant and comes after a bidding war between many of Hollywood's top studios, including Nolan's previous collaborator Warner Bros.

Oppenheimer was known as “the father of the atomic bomb" and the movie is based on the Pulitzer Prize-winning book 'American Prometheus: The Triumph and Tragedy of J. Robert Oppenheimer' by Kai Bird and the late Martin J. Sherwin.

The film will be written and directed by Nolan, who will also produce alongside Emma Thomas and Atlas Entertainment’s Charles Roven.

Universal Filmed Entertainment Group Chairman, Donna Langley said: "Christopher Nolan and Emma Thomas’ films have shattered the limits of what cinematic storytelling can achieve. We are thrilled to be working alongside them on this exceptional and extraordinary project and are grateful for their shared passion and commitment to the theatrical experience.”

Oppenheimer's story has been told on screen before, with 1989 drama 'Fat Man and Little Boy', starring Dwight Schultz as the scientist, and Paul Newman as General Leslie Groves.