Conviction of Klaus Fuchs

Date: March 1, 1950 • Location: London, United Kingdom

In a trial lasting less than 90 minutes, German–British physicist Klaus Fuchs was convicted of violating the Official Secrets Act by supplying information from the Manhattan Project to the Soviet Union.

Klaus Emil Julius Fuchs was a German theoretical physicist, atomic spy, and communist who supplied information from the American, British, and Canadian Manhattan Project to the Soviet Union during and shortly after World War II. While at the Los Alamos Laboratory, Fuchs was responsible for many significant theoretical calculations relating to the first nuclear weapons and, later, early models of the hydrogen bomb. After his conviction in 1950, he served nine years in prison in the United Kingdom, then migrated to East Germany where he resumed his career as a physicist and scientific leader.