Isaac Folkoff was a senior member of the California Communist Party USA and West Coast liaison between the KGB and the Communist Party. His role in Soviet espionage is documented by deciphered KGB cables (Venona) and the testimony of William Crane, a California Communist and photographer for Chambers’ espionage apparatus.
Folkoff was in charge of West Coast operations when he was a liaison between Soviet intelligence and the Communist Party USA (CPUSA). Folkoff worked as a courier passing information to and from Soviet sources, and as a talent spotter and vetter of potential espionage recruits. He also worked as a Case Officer. His code name in Soviet intelligence and in the Venona files was "Uncle."
According to "The shameful years; thirty years of Soviet espionage in the United States" page 39;
- "Isaac Folkoff, who has used the aliases Cam Falconvitch, and "Pop," is a naturalized American citizen of Latvian birth, who has been engaged in the clothing business in San Francisco. Folkoff has long exerted a strong influence on Communist Party leaders in the San Francisco area, and has been reported to control the strings of the party's secret funds there.
- During the course of meetings between Kheifets and Folkoff, Government agents frequently observed that Kheifets would depart from the meetings with an envelope or package that had been carried to the meeting by Folkoff.
- Folkoff is also known to have been in attendance at secret meetings with a group which included Steve Nelson, Haakon Chevalier, and William Schneiderman, head of the Communist Party in California. Folkoff also held clandestine meetings with Louise Bransten."
- "John Earl Haynes and Harvey Klehr, Venona: Decoding Soviet Espionage in America" (New Haven: Yale University Press, 1999), pgs. 234, 235, 239
- Biographical Dictionary of the Left, Francis X. Gannon, Vol. 4, p. 530