MI14
MI14, or British Military Intelligence, Section 14 was a department of the British Directorate of Military Intelligence. It was an intelligence agency of the War Office, which specialised in intelligence about Germany. Originally part of MI3, during the Second World War the German sub-department's expertise and analysis became so important to the war effort that it was spun off into its own Military Intelligence section.
One of MI14's most valuable sources, codenamed COLUMBA, consisted of reports returned by pigeons dropped over Nazi-occupied countries in packs containing a miniature spying kit.
Now defunct, the foreign intelligence remit is handled by the Secret Intelligence Service.