Portugal
During the war, Portugal, with neutral status, was one of the centres of tungsten production and sale to both Allied and Axis powers. Much of the tungsten was purchased with Nazi gold bullion, which was looted from the countries they had invaded. It is estimated that nearly 100 tons of Nazi gold were laundered through Swiss banks, with only four tons being returned at the end of the war.
During the war, Portugal was the second largest recipient of Nazi gold, after Switzerland, and this came through the sale of Wolfram (as tungsten was then called), with the German armaments industry nearly entirely dependent on the supplies from Spain and Portugal. Initially the Nazi trade with Portugal was in hard currency, but in 1941 the central Bank of Portugal established that much of this was counterfeit and Portuguese leader António de Oliveira Salazar demanded all further payments in gold.
Read more about this topic: Nazi Gold