Karl-Erich Kühlenthal  Major Karl-Erich Kühlenthal (1908 – October 25, 1975) was a German spy and one of the most senior agents in Spain during World War II. Kühlenthal was a "Mischling"—being "a half-blood Jew"—though Wilhelm Canaris had managed to secure an Aryan certificate for him in 1941. In 1943, when the body of major William Martin—a Royal Marine attached to Combined Operations—had washed up on a beach in Spain after a possible plane crash, Kühlenthal thought he had found important classified documents on the British major's body. In fact, the documents were false and the body that of Glyndwr Michael, a homeless Welsh man. These were part of Operation Mincemeat, a plan to convince the Germans that the Allies planned to invade Greece and Sardinia instead of Sicily. It is not certain if Kühlenthal was convinced by the documents, but he passed them on to his superiors, who "swallowed Mincemeat whole".