Giovanni Coco, archivist and researcher at the Vatican Apostolic Archives, told journalist Massimo Franco for the insert La Lettura of the Corriere della Sera that he discovered a 1942 letter in which a German anti-Nazi Jesuit, Lothar Konig, spoke explicitly to Pope Pius XII about the extermination of Jews by the Nazis, describing what was occurring in concentration and extermination camps in Germany and Poland during World War II. In the letter, photographed and reproduced by the newspaper, states, among other things: "In Rawa-Russka with its SS blast furnace, up to 6000 men die every day, mainly Poles and Jews." The letter, which was held in the Vatican Apostolic Archives but never investigated, is likely the most important proof unearthed to date indicating Pope Pius XII was aware of the Nazi camps' slaughter of Jews. The Vatican chose the path of transparency first by opening the Archives of that time period and now by bringing this significant document to light. It is now improbable that Pius XII's sanctification process will be able to continue.