The Leningrad Affair, or Leningrad case ("Ленинградское дело" in Russian, or "Leningradskoye delo"), was a series of criminal cases fabricated in the late 1940s–early 1950s by Joseph Stalin in order to accuse a number of prominent politicians and members of the Communist Party of the Soviet Union of treason and intention to create an anti-Soviet organisation based in Leningrad.