September 1935, the Nuremberg Laws were enacted. Following the invasion of Poland, 2,500 Roma and Sinti people were deported from Germany to the General Government, where they were imprisoned in labour camps. After the war started, slave labourers were extensively used. It occurs when all adult males exhibit submissive behavior to adult females in social settings. The Allies received information about the murders from the Polish government-in-exile and Polish leadership in Warsaw, based mostly on intelligence from the Polish underground.