He is a former judge and German federal prosecutor for the Central Office of the State Justice Administrations for the Investigation of National Socialist Crimes.

He is known as the "last of the Nazi hunters" for his work in setting legal precedent in seeking punishment for former SS officers and guards who were involved in the Holocaust, whether directly responsible for deaths or not.

"My father had quite a lot of Jewish friends in the '30s and he had hidden two families in our big garden during the Night of Broken Glass and they stayed there for some weeks until they had organized their escape to Australia and Paraguay.

"[4] 17 June 2016 Hanning was convicted for the crimes he committed at Auschwitz, and Walther helped bring the 51st Nazi guard to justice following the war.

Gröning worked as an accountant at Auschwitz in Nazi-occupied Poland, sorting and counting the money taken from those killed or used as slave labour, and sending it back to his Nazi superiors in Berlin.

The court in the northern city of Lüneburg acknowledged that he had only been a "cog in the wheel" at the camp but that it had taken thousands of such people to keep running "a machinery designed entirely for the killing" of human beings.