Colonel Aleksandr Feklisov, a Soviet spy whose long career included directing the intelligence-gathering of Julius Rosenberg, who was convicted of espionage and executed in 1953, and acting as intermediary between the White House and the Kremlin during the 1962 Cuban missile crisis, has died. He was 94.

Sergei Ivanov, head of the press service of the Russian Foreign Intelligence Service, announced the death, said Interfax, a Russian news service. Details of his death were not announced.

Feklisov was an intelligence officer for the Committee for State Security, best known by its Russian abbreviation, KGB, from 1939 to 1974, and a contract officer for the service from 1974 to 1986. He described his once-secret activities in a 1997 documentary on American television and in writings that include his autobiography, "The Man Behind the Rosenbergs."

He said he spoke in part to shed "glory" on Rosenberg and his wife, Ethel, who was also executed for espionage in 1953. He said Ethel Rosenberg was not a spy and that Julius Rosenberg gave the Soviets no atomic secrets, although he and those he recruited did provide valuable military information. He praised them as having put ideals, those of communism, ahead of patriotism to their own country.

The successor agency to the KGB has refused to comment on Feklisov's statements and writings. His claims that espionage speeded development of Soviet atomic weapons by 18 months contradict official statements that the country's own scientists were almost wholly responsible.