Pyotr Semyonovich Popov (Russian: Пётр Семёнович Попов; July 1923 – January 1960)[1] was a colonel in the Soviet military intelligence apparatus (GRU).
He was the first GRU officer to offer his services to the Central Intelligence Agency after World War II.
Between 1953 and 1958, he provided the United States government with large amounts of information concerning military capabilities and espionage operations.
[2] Popov first made contact in 1953 by slipping a letter into the parked car of a United States diplomat in Vienna, offering to sell Soviet documents.
He may also have been exposed by British double agent George Blake, who inadvertently learned the CIA was using a senior Soviet intelligence officer stationed in East Germany as a mole.