David Greenglass, US Cold War spy, 'died in July'
An American spy who passed nuclear secrets to the Soviet Union in one of the most high-profile espionage scandals of the Cold War has died.
David Greenglass, who was 92, stole atomic research data while working on the wartime Manhattan Project in Los Alamos, New Mexico.
After being arrested he then lied on oath and gave evidence which sent his own sister to the electric chair.
Greenglass's death was in July but it has only now been reported.
'I sleep well'
A native New Yorker, Greenglass secured a role on the Manhattan Project after being drafted into the army following the outbreak of World War Two.
The project was America's top secret attempt to develop the world's first nuclear weapon.
But Greenglass, a young convert to Communism, began passing highly classified information to his brother-in-law, Julius Rosenberg - a Soviet spy who was married to his sister Ethel.
After being arrested in 1950, Greenglass testified that during one meeting with Rosenberg he had seen Ethel typing up notes.
But speaking to a reporter years later he admitted that he had lied in order to save the life of his own wife Ruth, who had also been arrested after attending the same meeting.
Over the following years serious doubts began to emerge about Ethel's execution.
"As a spy who turned his family in... I don't care. I sleep well," he told the journalist in 2001.
The Rosenbergs were both executed for treason. Greenglass, meanwhile, served 10 years of a 15-year sentence for espionage and was released in 1960.
He died in New York City on 1 July, according to the Rosenbergs' sons, Michael and Robert Meeropol.
The brothers were aware of the death earlier but but did not seek media attention.