The Karski Report
The final scenes of Lanzmann's 1985 film Shoah figures the Polish resistance man and diplomat Jan Karski. Karski acquired during the war detailed first-hand information on the Holocaust in occupied Poland. He was instructed to convey them to the top politicians such as President Roosevelt and Jewish organizations in the West in hopes of measures to prevent the killings.
The film, an extended interview with Karski thirty years later, explains in detail and reflects on their experiences, including the highly skeptical reception he got from those he met.