Final answer:
Gunther was most likely imprisoned in Auschwitz.
Step-by-step explanation:
The context of the question suggests that Gunther was most likely imprisoned in Auschwitz. Auschwitz was one of the most notorious concentration and extermination camps during the Holocaust, known for its brutality and the killing of prisoners by the Nazi guards. The mention of SS officers and Hitler's directive not to answer to civil authorities also supports this conclusion.
Learn more about Holocaust and concentration camps