The Hauptverwaltung Aufklärung (HVA) (en. Main Reconnaissance Administration) of the former German Democratic Republic (GDR, "East Germany") was the foreign intelligence service of the GDR and was an integral part of the GDR Ministry of State Security (Ministerium für Staatssicherheit / MfS).
Hauptverwaltung Aufklärung, the defunct foreign intelligence service of the German Democratic Republic
As well as his research Vieweg also worked for the Main Intelligence Directorate of the Stasi.