 However, Grundmann also prospered as a "Secret Informer" ("Geheimer Informator") to the Ministry for State Security ("Stasi").He spied on (high ranking) theologians in Eastern and Western Germany.His cover name was "GM Berg" ("GM Mountain") after the Sermon on the Mount ("Bergrede") to which he referred in his inaugural speech 1939 at the Institute for the Study and Elimination of Jewish Influence on German Church Life, set up under him in Jena.