The Central Remand Prison of the Ministry of State Security (MfS) was located in the East Berlin district of Hohenschönhausen. In operation between 1951 and 1989, the institution processed some 11,000 prisoners during its existence. Also the location and centre of operations of Department HA IX of the MfS (responsible for investigating cases of political opposition) and run by a separate remand unit, the remand centre held inmates who had come into conflict with the SED regime for diverse reasons. Once arrested, they were subject to interrogation as part of a covert investigation. This study focuses on the central activities of the central MfS investigation department, the methods adopted by the Ministry of State security in its treatment and housing of the prisoners and the impact of these activities on the ways in which the judicial system was used to repress political opposition in the German Democratic Republic (GDR). Investigation of these topics also entails consideration of the position and significance assumed by this institution within the general mechanism of political repression in the GDR.