|Pyotr Semyonovich Popov was a
Soviet military intelligence officer with a rank of major.
He contacted Americans in Vienna in 1953 and offered his services as a spy for the United States.
For lack of recruiting results, Popov was ordered to return from Vienna to Moscow in late 1958.
Several CIA contacts were made with Popov in Moscow until his arrest in February 1959.
During the September 1959 Popov meeting with CIA operative, Pyotr Popow warned CIA that KGB was controlling all their contacts and meetings since the arrest in February 1959.
KGD allowed those meetings to learn more about CIA operations in Moscow until October 1959.
In October 1959 KGB arrested Popov and his CIA contact on the bus.
Popov used poison to kill himself to avoid interrogations.
Two KGB officers handling Popov then were demoted.