Oleg Penkovsky was born in Russia in 1919. He joined the Kiev Artillery School and became a lieutenant in 1939. A member of the Communist Party, he took part in the invasion of Finland and by the end of the Second World War had reached the rank of lieutenant-colonel.
In 1955 Penkovsky was appointed military attaché in Ankara. Later he was appointed to the Coordination of Scientific Research where he became deputy head of the foreign department. In April 1961 he began passing important information to his British contact in Moscow, Greville Wynne.
Penkovsky revealed information about Soviet missile developments, nuclear plans, locations of military headquarters and the identities of KGB officers. This included evidence that Nikita Khrushchev had been making false claims about the number of nuclear missiles in the Soviet Union. Over a period of 14 months Penkovsky passed photographs of 5,000 secret papers to the CIA and MI6.
Penkovsky, described by one intelligence officer as the "best spy in history", was considered so important that a meeting was arranged between him and Sir Dick White, head of MI6.
The Soviet Union had two double agents, William Whalen and Jack Dunlap, working in Washington. Eventually information was passed to the KGB that Penkovsky was spying for the West. On 20th October, 1962, Russian intelligence officers raided Penkovsky's apartment and discovered a Minnox camera that had been used to photograph secret documents.
After being convicted Wynne was sentenced to eight years' imprisonment and Penkovsky was sentenced to death. Oleg Penkovsky was executed on 16th May 1963.