Kurt Gerstein (1905-1945) was a German SS officer and head of technical disinfection services of the Hygiene-Institut der Waffen-SS. After witnessing mass murders in the Belzec and Treblinka Nazi extermination camps on August 17, 1942, Gerstein gave a detailed report to Swedish diplomat Göran von Otter, as well as to Swiss diplomats, members of the Roman Catholic Church with contacts to Pope Pius XII, and to the Dutch government-in-exile, in an effort to inform the international community about the Holocaust as it was happening.