Overview: Swiss banks stand accused of collaborating with the Nazis before and during the Second World War. But 60 years ago, when US Secretary of the Treasury Henry Morgenthau began investigating this collaboration, he found the Swiss were not alone. Tonight's film looks at Allied bankers - including British and Americans - who continued to do business with the Nazis during the war and how Morgenthau's inquiry led to some of the biggest names in British and American street banking. 4/6.