In 1943 the body of a British officer, Major William Martin, was discovered off the coast of Spain, near Huelva. British diplomats strongly requested that all documents found with the body be returned to them, and the Spanish government eventually complied. But upon examination, it was obvious the documents had been opened and read before their return. This was exactly what the British had hoped would happen, because Major Martin did not exist. He was part of a military hoax, codenamed Operation Mincemeat, designed to fool the Germans.
The British military had obtained a cadaver, chained a briefcase containing supposedly top-secret papers to its wrist, and dropped it in the sea off the coast of Spain. The plan was that the Germans, via the Spanish, would find the body and read the fake papers. The papers stated that the Allies' planned invasion of southern Europe would begin with an attack on Greece and Sardinia. In reality, the Allies planned to attack Sicily first. The hoax was successful. When the Allies launched their offensive on Sicily, most of the heavy German equipment had been moved to defend these other locations.
Ewen Montagu, the British officer who devised the operation, later wrote a book about it titled The Man Who Never Was
. The book was subsequently made into a movie.