Sergei Tretyakov, a top Russian spy working for the KGB at the United Nations who defected to the United States in 2000, has died of a heart attack. He was 53 years old. He was the most important spy for the United States since the end of the Cold War, wrote author Pete Earley in an excellent 2008 book about Tretyakov called Comrade J. At the time of publication, the headline revelation in the book was that the Russian government had stolen $500 million from the UN Oil-For-Food program.
He died on June 13th and an autopsy indicated that there were no signs of foul play. But it is widely believed that it was Tretyakov who tipped the FBI to the existence of the Russian spy ring that was finally rolled up ten days ago, just after his death.