Swiss intel to unveil secret file of Nazi doctor Josef Mengele

The secret file of the notorious Nazi doctor Josef Mengele will be unveiled to the public, the Swiss Federal Intelligence Service (NDB) announced last week.

Known as the “Angel of Death,” Mengele advanced the Nazi ideology’s racial ideology and carried out torture and experiments on prisoners of the Auschwitz concentration camp.

Unlike many other Nazis, he evaded capture after World War II. In 1949, he fled from Europe to South America, where he lived until his death in Brazil in 1979, reportedly by drowning.

In 2025, historian Gérard Wettstein requested access to the archives to determine whether Mengele had visited Switzerland in 1959, a move that ultimately led to the files’ release. He sought to determine whether Swiss authorities had secretly approved the Nazi doctor’s entry into the country. The documents had originally been sealed until 2071.

“It seemed ridiculous,” Wettstein said in an interview with the BBC. “As long as they are closed until 2071, it fuels conspiracy; everyone says ‘they must have something to hide,’” he said at the time.

The Mengele file was created by the Swiss Federal Prosecutor’s Office, the predecessor to the Swiss Federal Intelligence Service. In 2011, it was transferred to the Federal Archives, although the intelligence service continued to block public access. The most recent request for its release was reportedly submitted in February 2026. Following internal consultations, the matter was ultimately resolved in line with a 2001 Federal Council decision calling for a more liberal access policy to federal archival material.

The release of the file comes amid broader scrutiny of Switzerland’s conduct during the Holocaust and its wartime economic ties with Nazi Germany. In 1996, the Swiss government established the Independent Bergier Commission after facing a lawsuit from the World Jewish Congress, which accused Switzerland of withholding assets belonging to Holocaust victims. The commission reportedly also examined the status of the Mengele file.

NDB announced that Wettstein will be granted access to the Mengele file while stressing it would be “subject to conditions and restrictions that still need to be defined.”

“Requests for access to archived documents require careful balancing between the interests of research and the public on the one hand, and existing confidentiality concerns on the other – particularly the protection of sources and information from partner intelligence services,” Swiss intelligence stated.

Sacha Zala, who heads the Swiss Society for History, does not believe the file will reveal anything substantially new about the Nazi doctor.

“It shows the stupidity of the declassification process without historical knowledge,” Zala said. “In this way, the administration fueled conspiracy theories.”

Historian Jakob Tanner argued that the secrecy concerning the Mengele file constituted “a conflict between national security and historical transparency, and the former often prevails in Switzerland.”

“It is a problem for a democratic state that these files are still closed,” he added.

Wettstein also expressed skepticism concerning the released file, saying, “I fear we will get a file that is more black than transparent. He continued: “Why have these Mengele files been closed for so long? Maybe we will never get to the real truth.”

Christoph Heubner, executive vice president of the International Auschwitz Committee, believes it is a good step for authorities to declassify the file.

“For Auschwitz survivors, even many decades after their survival, Josef Mengele remains a name that makes their hearts turn cold and sends shivers down their spines,” Heubner said. “The fact that this very ‘Angel of Death of Auschwitz’ repeatedly escaped justice and the courts, and was able, probably for a period also in Switzerland, to live a largely relaxed and undisturbed life, still outrages and pains them to this day.”

Declassified Argentine intelligence files indicate that authorities were aware of Mengele’s presence in Argentina in 1959 and the years after, before moving to Brazil, but failed to coordinate efforts to apprehend him. The documents also suggest he was able to live under assumed identities with little effective interference from law enforcement.