Cillian Murphy starrer 'Oppenheimer' will be Christopher Nolan's longest film

Christopher Nolan's upcoming biographical film, Oppenheimer, will be the longest he’s ever made.

Fans should expect a three-hour-long viewing, according to a report by Puck News. The report claims the movie's runtime is even more than The Dark Knight Rises.

If the time remains the same post production, Oppenheimer will supersede Nolan's Interstellar as his longest theatrical feature. Interstellar registered a runtime of 2 hours and 49 minutes. The Dark Knight Rises, the last film of his acclaimed Dark Knight Trilogy, ran for 2 hours and 45 minutes.

Oppenheimer is written and directed by Christopher Nolan. Murphy plays J. Robert Oppenheimer, the American theoretical physicist credited with being the "father of the atomic bomb" for his role in the Manhattan Project.

A joint production between the United Kingdom and the United States, the film is based on American Prometheus, a biography written by Kai Bird and Martin J. Sherwin.

The film chronicles the life of theoretical physicist J. Robert Oppenheimer, the director of the Los Alamos Laboratory during the Manhattan Project, and the contributions he made towards the creation of the atomic bomb.

Supporting cast on the film includes Emily Blunt, Robert Downey Jr., Matt Damon, Rami Malek, Florence Pugh, Benny Safdie, Michael Angarano, Josh Hartnett and Kenneth Branagh.