Hans Bernd Gisevius

Gustav-Adolf Timotheus Hans Bernd Gisevius (14 July 1904 – 23 February 1974) was a German politician, ''Gestapo'' and ''Abwehr'' officer and diplomat during the Second World War. He was a member of the Military Resistance, who actively participated in the Oster Conspiracy and the 20 July Plot, being among the few survivors. A covert opponent of the Nazi regime, he also served as a liaison in Zürich between Allen Dulles, station chief for the American OSS, and the German Resistance forces in Germany.

Gisevius was a witness for the defense, during the Nuremberg trials, testifying in favour of Schacht, who was acquitted, and against Göring, Kaltenbrunner and Keitel. Provided by Wikipedia