Hitler's plot to completely destroy London with an atomic bomb was very nearly a success, a new documentary has revealed.
Scientists and naval historians in Norway have found the boat which Nazis were using to transport heavy water - an ingredient for nuclear reactors.
Winston Churchill ordered the sinking of the 170ft SF Hyrdo ferry in 1944 - without knowing what the ship's secret mission was.
It was a choice which is now believed to have saved England's capital city.
Evidence of this has been dragged up 460ft from the bottom of a Norwegian lake around 100 miles from Oslo.
National Geographic teams working on the Drain the Oceans series found 40 barrels of heavy water when they virtually lifted the vessel - more than enough to push Germany a huge way to becoming a nuclear power.
About a ton of heavy water was discovered on the lake’s bed – proof that, without the heroism of a few soldiers, the Fuhrer could have dropped an atom bomb on London and, in the words of one scientist, ‘turned the war in the blink of an eye’.
Lake Tinn Norway where National Geographic teams have centered their investigations into Nazi transportation of heavy water
Winston Churchill ordered the bombing of SF Hyrdo ferry in 1944 as it carted heavy water to Germany
Heavy water has a unique atomic structure and is coveted for the production of nuclear power and weapons.
Naval historian professor Eric Grove