Heinz Bruckner
From Tardis Wiki, the free Doctor Who reference
Heinz Bruckner was a spy who was working against the Nazis by working under cover as an officer. In 1941, he grew suspicious of Clara Oswald after her arrival and correctly believed that she wasn't from Berlin or even Germany. He pointed a gun at Clara, telling her that he knew that she wasn't a spy because he was a spy himself. (COMIC: The Instruments of War)