An amazing cache of files shows that J Edgar Hoover's FBI took claims of Hitler's survival seriously and a team was assigned to exploring scores of tip offs.
The astonishing documents detail how an Argentinean fugitive claimed he helped Hitler, two women and other Germans disembark from a submarine in the South American country approximately two and half weeks after the fall of Berlin in April 1945, the Daily Express reported.
Hitler and his companions then went by horse pack to the foothills of the southern Andes, and the plan was for the 50-strong group to move in with German families in villages in the area.
The unnamed Argentinian informant, who gave the information over to the US authorities hoping to get asylum in return, gives a description of Hitler to a journalist for the Los Angeles Examiner on July 29 1945, saying the Nazi "is suffering from asthma and ulcers, has shaved off his moustache and has a long 'but' on his upper lip".
Other tip-offs to the FBI suggested Hitler was actually living in New York City, again without his moustache, while some suggested he was hiding with Nazi sympathisers in the German speaking part of Switzerland.
The revelations come just weeks after a Nazi-hunting author claimed he had found a picture of Hitler which proved he died in Brazil aged 95.