Already in 1940, the Polish government-in-exile was informing the rest of the Allies (incl. the British, the US) about German crimes against civilians in occupi

Already in 1940, the Polish government-in-exile was informing the rest of the Allies (incl. the British, the US) about German crimes against civilians in occupied Poland. See: https://en.wikipedia.org/wiki/Karski%27s_reports https://en.wikipedia.org/wiki/Karski%27s_reports I don't know how much the Swedes knew at that point though... However, given that they were a modern state, they must have had some intelligence agency, and the Germans weren't really working that hard to cover up their crimes either.