Berlin historian Rainer Karlsch claims that the Nazis conducted three nuclear weapons tests in 1944 and 1945. But he has no proof to back up his theories.

The United States needed 125,000 people, including six future Nobel Prize winners, to develop the atomic bombs that exploded over Hiroshima and Nagasaki in 1945. The uranium enrichment facility alone, including its security zone, was the size of the western German city of Frankfurt. Dubbed the Manhattan project, the quest ultimately cost the equivalent of about $30 billion.

In his new book, "Hitler's Bomb," Berlin historian Rainer Karlsch claims Nazi Germany almost achieved similar results with only a handful of physicists and a fraction of the budget. The author writes that German physicists and members of the military conducted three nuclear weapons tests shortly before the end of World War II, one on the German island of Ruegen in the fall of 1944 and two in the eastern German state of Thuringia in March 1945. The tests, writes Karlsch, claimed up to 700 lives.

[read on at Spiegel]