Was it the work of a field marshal? MI5 spent years trying to decipher CROP CIRCLES amid fears they were being used to guide Nazi bombers

MI5 spent years trying to decipher crop circles amid fears they were being used to guide Nazi bombers, secret documents from the Second World War have revealed. The files, held in the National Archives, show how British spies suspected Nazi sympathisers were sending secret messages to the enemy using ground markings. Among the suspected codes was a mysterious marking in a cornfield that was shaped like the letter 'G', with its tail appearing to point to a munitions factory in Glascoed, Monmouthshire. Read more: http://www.dailymail.co.uk/news/article-2917963/Was-work-field-marshal-MI5-spent-years-trying-decipher-CROP-CIRCLES-amid-fears-used-guide-Nazi-bombers.html#ixzz3Pkih4oNe Follow us: @MailOnline on Twitter | DailyMail on Facebook