How did news of the holocaust spread from germany and other parts of europe?

As Hitler began to expand his rule and become a stronger political figure, he began to use propaganda to sway the public's opinion on the Jewish population. A common theme included the Nazis blaming the Jews for the negative effects of the Treaty of Versailles on Germany's economy, military strength, and more. Following the Nuremberg Laws, which were a set of anti-Semitic laws passed to deprive Jews of their human rights, many of them were moved into ghettos with other Jews where they'd eventually be sent to labor/death camps as WW2 continued. However, most people weren't aware of the atrocities committed during the Holocaust until after the war. Following the end of the war in Europe, the Nuremberg Trials (where Nazi leaders were held responsible for "crimes against humanity"), was held and rumors of death/concentration camps were confirmed to the public.