Iosif Romualdovich Grigulevich was a Soviet secret police (NKVD) operative active between 1937 and 1953, when he played a role in assassination plots against Communist and Bolshevik individuals who were not loyal to Joseph Stalin. This included the murders of claimed and actual Trotskyists during the Spanish Civil War including Andreu Nin Pérez, and an initial, failed assassination attempt against Leon Trotsky in Mexico.
