On 20 September 1985, international wire service reports carried a statement distributed by the official Soviet news agency TASS that one A. G. Tolkachev, whom it described as a staff member at one of Moscow’s research institutes, had been arrested the previous June trying to pass secret materials of a defensive nature to the United States. Subsequent news stories said Tolkachev was an electronics expert at a military aviation institute in Moscow who was compromised by former CIA officer Edward Lee Howard.
In October 1985, The Washington Post ran a story that described Tolkachev as “one of CIA’s most valuable human assets in the Soviet Union.” According to FBI affidavits related to the Howard espionage case that were made public, Tolkachev had provided information on Soviet avionics, cruise missiles, and other technologies. The Soviets subsequently publicly confirmed that they had executed Tolkachev in 1986 for “high treason.”
Fascinating and well worth reading.