Otto Hartmann (20 January 1904 – 14 March 1994) was an Austrian stage and film actor.
[1] Following Austria's incorporation into Nazi Germany, Hartmann acted as an informer for the authorities (Gestapo).
Hartmann was a member of the Österreichische Freiheitsbewegung (Austrian freedom movement, a nonviolent conservative catholic resistance group), whose goal was the liberation from National Socialism and the detachment of Austria from the German Reich.
He gave this information to the Gestapo, leading to the arrest of 450 members of the resistance movement, some of which were subsequently sentenced to death, others to long terms in prison.
On 22 November 1947, Hartmann was sentenced to life in prison by the People's Court in Vienna for denunciation resulting in death.