In 1943 SS-Sturmbannführer Georg Konrad Morgen, from the SS Court Main Office, began investigating corruption and criminal activity within the Nazi concentration camps system. He eventually prosecuted so many SS officers that by April 1944, Himmler personally ordered him to restrain his cases. Among the people he investigated was Karl Otto Koch, the commandant of Buchenwald and Majdanek, and husband of Ilse Koch — as well as Buchenwald's concentration camp doctor Waldemar Hoven, who was accused of murdering both inmates and camp guards who threatened to testify against Koch.