The first information about Nazi flying saucers was a series of articles by Italian turbine expert Giuseppe Belluzzo and the German scientist Rudolph Schriever who claimed to have developed flying saucers during the Nazi period.
Sir Roy Fedden (an Aeronautical engineer ) has stated that the only craft that could approach the capabilities attributed to flying saucers were those being designed by the Germans towards the end of the war. Sir Roy Feddon , Chief of the Technical Mission to Germany for the Ministry of Aircraft Production, stated in 1945:
“I have seen enough of their designs and production plans to realise that if they (the Germans) had managed to prolong the war some months longer, we would have been confronted with a set of entirely new and deadly developments in air warfare.”

Released into the public domain (by the author Alebo).
“When WWII ended, the Germans had several radical types of aircraft and guided missiles under development. The majority were in the most preliminary stages, but they were the only known craft that could even approach the performance of objects reported to UFO observers.”
http://en.wikipedia.org/wiki/Nazi_UFO
Why has this been hidden from us?