The British historian Stephen Dorril, in his MI6 Inside the Covert World of Her Majesty's Secret Intelligence Service asserts that Faragó was the 'most successful disinformer or dupe' concerning the presence of Nazis in South America.
However, Faragó's book "Aftermath: The Search for Martin Bormann" which details the Nazi presence in South America was based on both Faragó's own personal investigation and interviews in South America, and Argentinian intelligence documents (some of which are provided in the book) whose veracity was attested to by attorney Joel Weinberg. Moreover, French intelligence operative (during WWII - on the 'Resistance' side -,and later) and right-wing polemist Pierre de Villemarest justified  part of Farago's statements. Villemarest disagreed on the details of Bormann's survival, but agreed he did survive the escape from Hitler's Bunker. Villemarest states that Bormann was not a mere Soviet agent (like Heinrich 'Gestapo' Müller) but was smart enough to get free (after a few months or years) from the Soviets' 'protection'. The main point of agreement between Farago and Villemarest being the resolute assertion of a several-year survival of Bormann after the fall of Hitler's regime. Faragó's book 'Aftermath' contains several reproductions of genuine Argentinian secret police documents related to the life of Bormann after 1945.
^Original text is as follows: Investigating 'The Nazi Menace in Argentina', author Ronald Newton found that the historic record had been left 'booby-trapped with an extraordinary number of hoaxes, forgeries, unanswered propaganda ploys and assorted dirty tricks'. The most successful disinformer or dupe was the American Ladislas Faragó, 'a somewhat Hemingway-esque figure with a strong Hungarian accent and a confidential manner', whose 'good connections with the CIA and secret services of several European countries enabled him to investigate and publish on a non-attributable basis' a series of half correct tales.
Stephen Dorril, MI6 Inside the Covert World of Her Majesty's Secret Intelligence Service, Tochstone 2002 ISBN 978-0-7432-1778-1 p.95
^The Bormann documents Weinberg states: "I personally interrogated several of the special agents whose names were mentioned in or whose signatures appeared on the documents, including Inspector Hector Rodriguez Morguado of Coordination Federal and Commissioner Alejandro Rafaelo of Policia Federal, and ascertained that the documents in Mr. Farago's possession bearing on the Bormann case were, indeed, genuine, and originated as claimed at the Seguridad Federal, formerly known as Coordination Federal, the central archives of the Argentine Secret Service Establishment. Based upon my investigation and my questioning of the parties concerned in the acquisition of the documents, I have no hesitation to state that the classifed [sic] documents on which the Bormann part of "Aftermath" is based are genuine and authentic, true copies of the originals on file at the agency until recently called Seguridad Federal in Buenos Aires."
^"Untouchable: Who protected Bormann & Gestapo Müller after 1945", Aquilion (2005), ISBN 1-904997-02-3