In June 1953, husband and wife Julius and Ethel Rosenberg were executed by electric chair after being convicted of conspiracy to espionage.

The trial and execution of the Rosenbergs took place as the United States was gripped by a climate of fear and paranoia about the threat posed by Communism.

They were the only people in the United States ever executed for Cold War espionage.

The couple's two sons, Robert and Michael, were six and 10 when their parents were executed. Robert told Witness about his memories of his parents, and the campaign to exonerate his mother Ethel.

Witness is a World Service programme of the stories of our times told by the people who were there.