Paul Thummel - A 54

Thümmel, Paul - Code name A 54 - Dresden-based high ranking member of the Abwehr who, from March 1937, supplied Czechoslovakia with reliable information about Germany's intentions and order of battle. He continued to do so via the Czech underground when the Czech government-in-exile was established in the UK. Code-named A-54, Thümmel's intelligence was passed to both MI6 and the USSR and helped maintain the credibility of Edvard Beneš, the exiled Czech leader. Thümmel was a highly decorated Nazi Party veteran and so many protests followed his arrest in October 1941 that the Gestapo released him. Rearrested the following March, he was imprisoned without trial and allegedly murdered by his SS guards a few days before the war ended. The motives for his treachery remain a mystery. He received payments, but not enough to compensate for the dangers to which he exposed himself, and the information he passed was too valuable for him to have been a double agent.

(source: www.encyclopedia.com)