Hundreds of newly discovered photographs, including some taken at the Sobibor death camp, represent a "quantum leap" in research into Nazi crimes against humanity, historians at the Berlin museum Topography of Terror said Tuesday. Historians said the "exceptional collection" provided unprecedented insights into the Sobibor camp in German Nazi-occupied Poland, about which little is known even 75 years after the end of World War II. The trove, consisting of 361 black-and-white photos and several written documents, also includes photos believed to show convicted Nazi guard John Demjanjuk, who denied ever being at Sobibor.