 He was then transferred to the prison in Smolensk, the NKVD Lubyanka Prison and then to Butyrki Prison in Moscow.After roughly a year of interrogation, his pre-war books on Soviet economy were interpreted as espionage, for which he was sentenced to 8 years in the Gulag.Transported to "Ust-Vym Camp" in Komi Republic, he was released from the prison camp following the Sikorski-Mayski Agreement in August 1941.