History records that Nazi dictator Adolf Hitler killed himself in his Berlin bunker as Soviet troops swarmed into the German capital on April 30, 1945.

But the founder and long-time director of the Federal Bureau of Investigation, J. Edgar Hoover, didn’t buy the story and authorized a mission to hunt down the infamous dictator in Argentina.

According to recently declassified FBI documents, the agency spoke of Hitler in the present tense and gave the agents sent to the South American country to capture him a physical description of the Nazi leader.

The International Business Times reports that Hitler was described by the documents as “suffering asthma and ulcers, and has shaved off his moustache.”

An informant for the intelligence service warned that the Fuehrer was holed up in a heavily defended compound and it would be a dangerous task to approach it.

The declassified documents follow a Brazilian author claiming that Hitler escaped Germany, fled to Brazil, settled down with a black wife, and lived to be the ripe old age of 95. The author, Simoni Renee Guerreiro Dias, backs up her claim with a photograph of a German immigrant who sort of looks like the dictator when you draw a toothbrush mustache on him.

Despite the theories, the overwhelming majority of historians believe Hitler killed himself with a combination of a cyanide tablet and a gun shot to the head near the end of World War II. Several witnesses were in the bunker when he killed himself.

But in spite of the unverified claims that Hitler survived the war, several top Nazis were able to flee to South America and escape immediate prosecution for their crimes.

Adolf Eichmann, one of the organizers of the Holocaust, fled to Argentina and was able to elude detection until he was captured by Israeli agents in 1960.

Klaus Barbie, an SS officer wanted for torturing prisoners of war, and Josef Mengele, the notorious “Angel of Death” of Auschwitz, also were able to escape to South America following the conclusion of the war.

Follow Scott on Twitter