Organization and methods of the O.G.P.U: Two British Documents from 1933

On March 27th, 1933 a British MI5 officer Oswald Allen Harker received a report on the inter+relation of the Comintern, GPU and Department IV of the Staff of the Red Army. The source of this report was a Jewish communist. Another report received by Harker, on the same day, was the OGPU method of investigation. He informed his superiors that the source of this document was the first-hand source. This article presents these documents because they are relevant to the level of knowledge of MI5 about Russian Espionage and subversive activity at that moment.