Documents revealing how infamous Nazi doctor Josef Mengele, known as the "Angel of Death," led an open post-war life in Argentina were found among a massive trove of evidence released and declassified earlier this year by President Javier Milei.
Mengele was notorious for his role as a commander in Auschwitz, where he conducted brutal medical experiments on prisoners, especially twins, under the guise of scientific research. Eyewitnesses — including some contained in the declassified Argentine files — describe his extremely cold-blooded and macabre, sadistic nature, including torturing and testing on twins in front of one another after sending their parents to the gas chambers.
An entire binder is dedicated exclusively to following the footsteps of infamous Auschwitz doctor and SS commander Mengele.
The declassified archives show Argentina clearly understood by the mid- to late 1950s who Mengele was and that he was actually present in the country. Authorities knew he had entered the country in 1949 using an Italian passport issued under the name Helmut Gregor, which he used as the basis for obtaining an official immigrant ID card in 1950.
In 1956, trying to expand his business partnership, he obtained a legalized copy of his original birth certificate from the West German Embassy in Buenos Aires, requested his ID be judicially amended to reflect his real biographical data and — surreally — began using his original legal name, a sign of how safe he felt in Argentina.
Argentine agencies by this point not only knew who he was, where he lived, and the fact that he married his brother’s widow and was raising their son, but also had full details regarding his business interests in the country. Reports in the files cite a possible visit by Mengele’s father to Argentina to help him financially, investing in a medical laboratory business in Buenos Aires.
The overt nature of his life in the country prompted West Germany to issue an arrest warrant and request his extradition in 1959, which was denied without further action by a local judge, citing that the request was unofficially based on "political persecution" of Mengele, which didn't allow for the case to be taken up.
Despite all the hard evidence accumulated, it is clear that the information was fragmented among various different agencies that did not fully communicate with one another. There was also a lack of direct communication with the country’s presidency and executive branches. This led to action on the case being decided in a disconnected manner, and often too late — or after press leaks had already alerted Mengele of possible concern by authorities — to yield fruitful results. Arrest warrants, searches, and surveillance requests were often carried out or decided after the fact, leading to dead ends.
After the 1959 extradition request and with increased international pressure on Argentina, Mengele escaped the country to Paraguay, while his wife and stepson moved to Switzerland.
This is evident from a memo from the Federal Coordinate Directorate marked as strictly secret and confidential detailing a search for Mengele and his business interests dated July 12, 1960 — a point when Mengele had already left Argentina for Paraguay.
"I bring to the knowledge of the Chief that from the investigations carried out in order to fulfill the referenced O.B., it follows that JOSÉ MENGELE, served as a partner of the medical laboratories ‘FADRO-FARM’ located at Drysdale 3573 Street, in Carapachay, District of Vicente López, and with offices, since July of this year, at Cramer 860 Street, Capital. The subject, listed as a medical doctor, was entered into the firm on July 10, 1958, as a contributing partner of $10,000 pesos in capital, and withdrew from the partnership in April of 1959," the report stated.
"Since entering Argentina, the subject resided on the property of the Mengeles, using the name of Dr. GREGOR […], the subject manifested that he had arrived in Argentina using a different name and distinct from his profession […]. Thus, it appears that, while maintaining his real name, the subject belonged to the SS Society […] during which time he demonstrated being nervous, having stated that during the war he acted as a physician in the German S.S., in Czechoslovakia, where the Red Cross labeled him a ‘war criminal.’ He had studied Anthropology and was known to the Justice in the courts of Nuremberg, especially regarding the study of skulls and bones, but that union was considered a crime in National Socialist Germany," the report states about Mengele when, in the course of changing his name from his fake alias to his real identity, the Nazi "explained" his motives for originally not using his real identity, it said.
Argentina’s intelligence community kept following Mengele, mostly through press reports and contacts with foreign agencies. Mengele acquired Paraguayan citizenship and was protected by the government of Paraguayan dictator Alfredo Stroessner, whose family originated in the same Bavarian town as him.
The archives reveal Mengele entered Brazil clandestinely at some point in 1960 through the tri-border area near Paraná state. He was helped by German Brazilian farmers who were Nazi sympathizers and provided multiple rural safehouses for several years.
Though the Argentine files are thin on details and rely heavily on media clippings at this point, Argentina was aware that Mengele had adopted the alias Peter Hochbichler, though sometimes he also used a Portuguese version of his real name — José Mengele. For the latter part of the 1960s and throughout the 1970s, he began living in properties belonging to the German Bossert and Stammer families in São Paulo state, Brazil.
Mengele died in 1979 when he suffered a stroke while swimming at sea in the coastal town of Bertioga. He was buried under the false name of Wolfgang Gerhardt, but multiple leads led to his body being exhumed and his remains being positively identified by Brazilian authorities in 1985. DNA testing further confirmed the findings in 1992.