The sons of Julius and Ethel Rosenberg say David Greenglass — a key figure in the biggest atomic spying case of the Cold War — has died at age 92.

Greenglass died July 1, according to Michael and Robert Meeropol.

Greenglass served 10 years in prison for his part in a plot to steal atomic secrets for the Soviet Union. He gave testimony that sent the Rosenbergs — who were his sister and brother-in-law — to the electric chair in 1953.

Decades later, Greenglass admitted lying on the stand about his sister's role.