Atomic bomb movie 'Oppenheimer' crowned best picture at the Oscars

"Oppenheimer," the blockbuster biopic about the race to build the first atomic bomb, claimed seven Academy Awards including the prestigious best picture trophy on Sunday as Hollywood celebrated a triumphant year in film.

Irish actor Cillian Murphy won best actor for playing theoretical physicist J. Robert Oppenheimer, leader of the US effort in the 1940s to create a weapon that ended World War Two. "Oppenheimer" director Christopher Nolan took home the directing Oscar.

"We made a film about the man who created the atomic bomb, and for better or worse we are living in Oppenheimer's world," Murphy said as he held his trophy on stage. "So I would really like to dedicate this to the peacemakers everywhere."

A three-hour historical drama about science and politics, "Oppenheimer" became an unlikely box office hit and grossed $953.8 million, in addition to widespread critical praise.

Robert Downey Jr. poses after winning the Oscar for Best Actor in a Supporting Role for "Oppenheimer". AFP

It was the first of Nolan's films to win best picture. The director has previously won acclaim for "The Dark Knight" Batman trilogy, "Inception," "Memento" and other movies.

As he accepted his gold statuette, Nolan noted that the movie business was a century old and still evolving.

"To know you think I'm a meaningful part of this means the world to me," he said.

Reuters