Melita Norwood, a British woman who was unmasked as a Soviet spy a decade ago, died June 2 at age 93.

Norwood, who admitted passing nuclear secrets to the Soviet Union, was exposed by Vasily Mitrokhin, who defected to Britain with a trove of KGB documents in 1992.

Norwood joined the Communist Party in the 1930s,and had access to British atomic secrets through her office job at the British Non-Ferrous Metals Research Association. The association was involved in metallurgical research associated with the atomic bomb project.

When her activities became publicly known in 1999,Norwood told reporters: “I did what I did not to make money, but to help prevent the defeat of a new system which had, at great cost, given ordinary people food and fares which they could afford, a good education and a health service.

“I thought perhaps what I had access to might be useful in helping Russia to keep abreast of Britain, America, and Germany.

“In general I do not agree with spying against one’s country.”

The government decided against prosecuting her.

The daughter of a Latvian father and an English mother, Norwood held fiercely left-wing views from an early age. She began spying for the Soviet Union four years after Josef Stalin took power, working under the code name “Hola.”

She passed top-secret documents from the Tube Alloys project – the cover name for the nuclear weapons program – to her KGB handlers.

The information she passed to Stalin’s government is said to have helped the Soviets build an atomic bomb two or three years earlier than they otherwise would have. But her activities never made her rich, and she continued to live in the rather basic London house she bought with her husband in the 1950s.

In 2000, a parliamentary committee that oversees intelligence agencies criticized the government for failing to prosecute Norwood.