Via two posts from Sullivan, I have learned that the two most successful interrogators and spybusters from WWII, one German and one British, never harmed an inmate.

No German won as many intelligence coups as Hanns Scharff. Scharff worked for the Luftwaffe interrogating allied pilots and bomber crews, so successfully that the U.S. military taught his methods decades later.

Colonel Robin “tin eye” Stephens was a “bristling, xenophobic martinet” who ran a famously successful counterinelligence operation for MI5 out of a basement in London.

In the course of the war, some 500 enemy spies from 44 countries passed through Camp 020; most were interrogated, at some point, by Stephens; all but a tiny handful crumbled. […] Many became double agents, secretly working for the British and sending false information back tocaptivity. […] After a prisoner’s fear had calmed, Scharff continued to act as a good friend to the prisoner, including sharing jokes, homemade food items, and occasionally alcoholic beverages. Scharff was fluent in English and knowledgeable about British customs and some American, which helped him to gain the trust and friendship of many of his prisoners.

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Stephens cared not for morality but for results, and these were extraordinary. Once a prisoner in Camp 020 realised he was safe from physical violence, he tended to sing all the louder.

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Some high profile prisoners were treated to outings to German airfields (one POW was allowed to take a German aircraft for a trial run), tea with German fighter aces, swimming pool excursions, and luncheons among other things. Prisoners were treated well medically