According to the Guardian…

A book published in Italy today is set to reignite a smouldering controversy over how close the Nazis came to manufacturing a nuclear device in the closing stages of the second world war.
The 88 year-old author, Luigi Romersa, is the last known witness to what he and some historians believe was the experimental detonation of a rudimentary weapon on an island in the Baltic in 1944.

Read more at http://www.guardian.co.uk/international/story/0,,1581375,00.html