This Der Spiegel article considers a new book, Hitler’s Bomb, by a German historian named Rainer Karlsch.
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.
The trouble is that the author, according to Der Spiegel, hasn’t proven this. At least the article is worth reading, even if the book may not be.