On 18 August 1943, Aumeier was found guilty of corrupt practices and theft of gold from the victims of gassing,[2] and as a result, was transferred from Auschwitz on the personal orders of Commandant Rudolf Höß.

He was attached to the SS-Construction Brigade of 5th SS Panzer Corps; this unit was responsible for building fortifications in the area Oranienbaum-Leningrad and was under the command of Organisation Todt.

Here, Aumeier took part in his only frontline engagement with the enemy as his unit attempted to attack the Estonian island of Osel (Saaremaa) but was unsuccessful.

When Aumeier was finally discharged, he reported back to Oranienburg and was asked whether he wanted to go to occupied Norway to become commandant of a new concentration camp at Mysen.

On 22 January Aumeier arrived in Oslo, met Pauly and was told he had to supervise the building of a camp to house approximately 3,000 prisoners to be used in slave labour.

In 1946, he was extradited to Poland to face trial as a war criminal along with thirty-nine other members of the SS staff of Auschwitz-Birkenau, before the Supreme National Tribunal in Kraków.

The trial lasted from 25 November to 16 December 1947, and Aumeier stated that if he was found guilty and sentenced to death, he would "die as a 'Sündenbock' (scapegoat) for Germany".