From 28 December 1945 to 4 January 1946, seven Wehrmacht servicemen were tried by a Soviet military court in Leningrad.
At the London conference that drew up the indictments of German war crimes before the Nuremberg trials, the Soviet negotiators put forward the allegation, "In September 1941, 925 Polish officers who were prisoners of war were killed in the Katyn Forest near Smolensk".