At the height of the Cold War, the Central Intelligence Agency paid $3,000 to renowned magician John Mulholland to write a manual on misdirection, concealment, and stagecraft. All known copies of the document — and a related paper, on conveying hidden signals — were believed to be destroyed in 1973...
http://www.wired.com/dangerroom/2009/11/cias-lost-magic-manual-resurfaces/