Abwehr
The Abwehr was the German military intelligence service from 1920 to 1945. From 1935 to 1944, Wilhelm Canaris lead the organization. At some point. he became a member of the German resistance, sabotaging Germany's foreign policy and war effort, providing the Allies with information, and providing important support for the German resistance. This has been argued to have been an important cause of Germany losing the war.
Deputy head Hans Oster and other Abwehr personnel were also part of the German resistance.
See also
- National Socialist Germany and partisans/resistance movements: Internal German resistance movements
- Holocaust documentary evidence: German resistance - Regarding absent Holocaust knowledge by the Abwehr.