Sergei Tretyakov, a former top Russian spy who defected to the United States after running espionage operations from the United Nations, has died in southwest Florida, his wife and a friend said Friday. He was 53.
News of his June 13, 2010, death came the same day the United States and Russia completed their largest spy swap since the Cold War.
His widow, Helen Tretyakov, asked friends not to make the death public until the cause was determined, according to author Pete Earley, who wrote a 2008 book about Mr. Tretyakov.
His defection in 2000 was one of the most prominent cases involving Russia's intelligence agency in the past decade. He and his wife lived quietly in the small town of Osprey.
WTOP Radio in Washington first reported his death Friday. Helen Tretyakov told the station he died of natural causes.
She said her husband warned the United Statesthat Russia was expanding deep-cover operations.
"He was aware that the part of the SVR budget for supporting illegals increased dramatically in the 1990s," she told WTOP. The SVR is the Russian intelligence agency that succeeded the KGB. However, she said there was no direct link between his information and the 10 people arrested last month as Russian spies near Boston, New York and Washington.