Declassified: files reveal how Nazi war criminal Josef Mengele lived in Buenos Aires
The archives offer a rare glimpse into Argentina’s postwar handling of Nazi fugitives, and local networks that enabled Mengele to live openly for over a decade
Newly declassified Argentine documents reveal that notorious Nazi doctor Josef Mengele, infamous for his brutal experiments at Auschwitz, lived openly in Argentina after World War II.
The files, released earlier this year by President Javier Milei, detail how Argentine authorities tracked, but often failed to act against, one of history’s most wanted war criminals.
Mengele, who conducted lethal experiments on twins and other prisoners, entered Argentina in 1949 under the alias Helmut Gregor and obtained official immigration papers by 1950.
The archives show he lived in Buenos Aires, married his brother’s widow, raised a family, and ran businesses, all while being monitored by fragmented intelligence services.
The collection includes surveillance reports, photographs, correspondence, and intelligence notes, shedding light on the networks that helped him move across Argentina, Paraguay, and eventually Brazil.
Testimony from Auschwitz survivor José Furmanski, also included in the files, confirms Mengele’s sadistic experiments, some of which were documented by Argentine intelligence.
Despite clear evidence of his identity and location, a 1959 extradition request from West Germany was denied, and bureaucratic inefficiencies allowed Mengele to evade capture. He ultimately settled in Brazil under false identities, where he died in 1979. His remains were later exhumed and positively identified through DNA testing.
The archives offer a rare glimpse into Argentina’s postwar handling of Nazi fugitives, highlighting the challenges of intelligence coordination, political hesitancy, and local networks that enabled Mengele to live openly for over a decade. They underscore the complex legacy of wartime criminals hiding in South America and the international efforts to track them.