Karski's reports were a series of reports attributed to Jan Karski, an investigator working for the Polish government-in-exile during World War II, describing the situation in occupied Poland. They were some of the first documents on the Holocaust in Poland received by the Polish government in exile, and, through it, by the Western Allies. For the 1942 report attributed to him, considered a cornerstone of his legacy, the attribution to Karski is unconfirmed. No reliable sources exist for the actual content of the information Karski carried with him to the West, and the information contained in the official reports may actually have come from other couriers. Reports Karski, who fought as a non-commissioned officer during the German invasion of Poland in 1939 and subsequently escaped from a prisoner-of-war transport, wrote his first report on the situation in Poland in late 1939. Subsequently, he escaped from Poland to France, where he joined the recreated Polish Army, and after coming to the attention of the Polish government-in-exile due to qualities like his photographic memory, he became a courier and an investigator, travelling several times between occupied Poland and France (later, the United Kingdom). His reports contained information about various aspects of the situation in occupied Poland, including topics such as the extent of Polish resistance, and on numerous German war crimes and atrocities, including the ongoing Holocaust, at that point mostly unknown in the West. His first two reports delivered to the government in exile in 1940 were entitled "Selected political and ideological issues in Poland" and "The Jewish situation". Joshua D. Zimmerman called his work the "Home Army's first comprehensive report on the situation of Polish Jews". and David Engel referred to it as "the first comprehensive discussion of Jewish matters in occupied Poland to have reached the [Polish] government [in exile]. His first report, compiled in France in 1940, was commissioned by a Polish leader Stanisław Kot, who asked Karski to write up his observations on several issues, among them, implicitly, the situation of the Polish Jews. Karski wrote several more reports in the following years. His fourth report was also focused on the plight of the Jews. For the 1942 report attributed to him, considered a cornerstone of his legacy, the attribution to Karski is unconfirmed. No reliable sources exist for the actual content of the information Karski carried with him to the West, and the information contained in