German-born physicist Klaus Fuchs played a key role in the development of the first atomic bomb during World War Two.

The project, known as the Manhattan Project, was led by scientist J Robert Oppenheimer at Los Alamos in the US.

But, in January 1950, Fuchs admitted passing top secret nuclear secrets to the Soviet Union and was sentenced to 14 years in jail.

His nephew Klaus Fuchs-Kittowski tells Louise Hidalgo about his uncle.

This programme was first broadcast in 2015.

To hear more about the story of Klaus Fuchs, the spy who changed history, search for The Bomb, wherever you get your BBC podcasts.

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(Photo: Klaus Fuchs. Credit Jung/ullstein bild via Getty Images)

Klaus Fuchs: Oppenheimer’s atomic spy

Witness History

Klaus Fuchs: Oppenheimer’s atomic spy