Jonathan Forbes

Jonathan Forbes played Trevor Gale in the audio story Night of the Stormcrow, Dr Sturgis in the audio story The Great War, Patrick O'Sullivan in the audio story Tangled Web, and Kurt Schalk in the audio stories Persuasion and Daleks Among Us (although he was credited as playing Lukas Hinterberger in both stories).

Trivia
Forbes' roles of Patrick O'Sullivan and Kurt Schalk make him the only person to have played the fathers of two different companions.