This was a Polish resistance propaganda operation designed to discredit Generalfeldmarschall Walter von Reichenau, commander of the German 6th Army on the Eastern Front, in the eyes of the German leadership (January 1942).
Carefully disseminated in the right places, the Polish propaganda was designed to suggest that that von Reichenau was plotting to overthrow the Nazi régime, thus sowing distrust between the Nazi political leadership and its military command, and at the same time bringing about the possible punishment of one of the German generals responsible for war crimes in Poland.
On 15 January 1942 Reichenau suffered a stroke after a trail run in harsh cold weather, and it was decided to fly him from his headquarters at Poltava behind the Eastern Front to a hospital in Leipzig in Germany. He is often said to have been killed in a an aeroplane crash in the German-occupied western part of the USSR, but it seems that the aeroplane in fact made an emergency landing in a field and that Reichenau actually died of a heart attack on 17 January.
von Reichenau’s death coincided with the Polish propaganda offensive, and the coincidence of the propaganda effort with von Reichenau’s death became a fertile ground for conspiracy theories, which allege that von Reichenau might have been killed by the Nazi secret services.