Kurt Schalk

Hauptsturmführer Kurt Schalk was a Nazi scientist and the creator of the persuasion machine. He recognised Elizabeth Klein, thinking her to be someone else. He told Will Arrowsmith about the creatures that were looking for the machine, including the Sontarans. (AUDIO: Persuasion) To prevent the machine from falling into the wrong hands, he used the machine on himself and his assistant Lukas Hinterberger to make them believe they were each other. Thus, anyone who would come seeking the machine would focus on Hinterberger instead of Schalk. (AUDIO: Starlight Robbery)

The Daleks used their techniques to make him remember his true identity. He was to be re-educated in an Azimuth facility, this was after the Dalek surgery. The Seventh Doctor and Elizabeth Klein talked to him here, he had lost his accent, until he remembered the Daleks. This was in fact a clone, so that the Daleks could get information on the Persuasion Machine. The Supreme Dalek consided to his demands and led to believe he was the Fuhrer of the Daleks. He used Will to persuade the Doctor to tell him where Klein had gone. He was also the biological father of Elizabeth Klein, he looked after her in his bunker. He told the Doctor that Klein was made to operate the machine. (AUDIO: Daleks Among Us)

Behind the scenes
Because of the identity switch, in Persuasion the credit for playing Schalk went to David Sibley.