My grandma worked as a civil servant in Russia near one of the worst camps. She saw a huge store room where all the furniture and stuff of the Jews were kept. She was told they were from citizens who had fled.

When her department moved to another building they got some ultra thin mangled "prisoners" to help with the move. They were told that these prisoners were murderers and rapists so it was ok that they were malnourished.

A few weeks later the war had ended (and she was back in Germany) and she got the news of what was really going on, basically next door.

She was a naïve young woman back then.

Once a friend of hers was about to have an audience with Hitler and she asked her to tell him about the bad situation in the city. She didn't know the half of how "bad" it really was. Her perspective was that supplies were really low and that the general populace was suffering. Surely the almighty Führer would be able to do something to change things. The response from him was that "they shouldn't heed those crazy conspiracy stories".