In 1942, with the territory around Smolensk under German occupation, captive Polish railroad workers heard from the locals about a mass grave of Polish soldiers at Kozelsk near Katyn; finding one of the graves, they reported it to the Polish Underground State. The discovery was not seen as important, as nobody thought the discovered grave could contain so many victims. In early 1943, Rudolf Christoph Freiherr von Gersdorff, a German officer serving as the intelligence liaison between the Wehrmacht's Army Group Centre and Abwehr, received reports about mass graves of Polish military officers. These reports stated the graves were in the forest of Goat Hill near Katyn. He passed the reports to his superiors (sources vary on when exactly the Germans became aware of the graves—from "late 1942" to January–February 1943, and when the German top decision makers in Berlin received those reports early as 1 March or as late as 4 April). Joseph Goebbels saw this discovery as an excellent tool to drive a wedge between Poland, the Western Allies, and the Soviet Union, and reinforcement for the Nazi propaganda line about the horrors of Bolshevism, and American and British subservience to it. After extensive preparation, on 13 April, Reichssender Berlin broadcast to the world that German military forces in the Katyn forest near Smolensk had uncovered a ditch that was "28 metres long and 16 metres wide by 52 ft, in which the bodies of 3,000 Polish officers were piled up in 12 layers". The broadcast went on to charge the Soviets with carrying out the massacre in 1940.