Oslo report

Oslo report, two letters sent incognito to the British naval attaché in Oslo in November 1939 and forwarded for assessment to the MI6 scientist, R. V. Jones. They contained descriptions of the German development of various types of armament, including V-weapons and radar, and one also included the triggering device for a proximity fuze which was superior to anything the British had at the time. Jones had no doubt as to the veracity of the letters, but he could find no one else who would take their contents seriously. It transpired that most of the report was remarkably accurate. It helped Jones counter the various German beam systems that guided German bombers on to their targets (see electronic navigation systems and electronic warfare), and as the war progressed Jones took to referring to the letters to see what was likely to appear next.

The identity of the report's author, a German physicist called Hans Ferdinand Mayer who worked for the electronic firm Siemens, remained unknown until 1989 when Jones revealed it in his book Reflections on Intelligence, which contains the complete report (pp. 333–7). Because of his anti-Nazi stance Mayer was imprisoned in Dachau in 1943 but survived the war to become professor of astrophysics at Cornell University in the USA. Jones judged his report the best received from any single individual during the war, Mayer having ‘in one great flash…given us a synoptic glimpse of much of what was foreshadowed in German military electronics’ (Reflections on Intelligence, London, 1989, p.275).