Switzerland’s Federal Intelligence Service has announced it will open long-sealed files related to Nazi war criminal Josef Mengele, the Auschwitz doctor known as the “Angel of Death,” after years of pressure from historians seeking access to the documents.
The files, however, are not expected to be released immediately as reported in BBC. Swiss authorities said access would be granted “subject to conditions and requirements yet to be defined,” leaving uncertainty over how much information will ultimately become public.
Mengele, an SS doctor at the Auschwitz extermination camp in Nazi-occupied Poland, was responsible for selecting prisoners to be sent to the gas chambers and conducting brutal medical experiments, particularly on children and twins. Historians estimate that as many as 400,000 people were sent to their deaths under his supervision.
Visitors enter the Hall of Names to look at pictures of Jews killed in the Holocaust during a visit to the Holocaust History Museum at the Yad Vashem World Holocaust Remembrance Center in Jerusalem January 15, 2020. Picture taken January 15, 2020. REUTERS/Ammar Awad
After World War Two, Mengele escaped Europe using false documents issued through the International Committee of the Red Cross office in Genoa, Italy, eventually fleeing to South America. The Red Cross later apologized for war criminals obtaining such travel papers.
Questions over Mengele’s possible ties to Switzerland have persisted for decades. It has long been known that he visited the Swiss Alps with his son in 1956. But historians have increasingly focused on whether he may have secretly returned after 1959, when an international arrest warrant had already been issued against him.
FILE PHOTO: Inmates are seen lying on bunks in a barrack at Nazi German death camp Auschwitz-Birkenau after its liberation in 1945 in Nazi-occupied Poland, in this undated handout picture obtained by Reuters on January 19, 2020. Courtesy of Yad Vashem Archives/Handout via REUTERS/File Photo ATTENTION EDITORS – THIS IMAGE WAS PROVIDED BY A THIRD PARTY
Swiss historian Regula Bochsler uncovered evidence suggesting Austrian intelligence warned Swiss authorities in 1961 that Mengele might be travelling through Switzerland under a false identity. At the same time, Mengele’s wife reportedly rented an apartment in Zurich and applied for permanent residency.
Bochsler also found Zurich police records showing the apartment was placed under surveillance, including reports of Mrs Mengele being seen with an unidentified man. Whether that man was Josef Mengele has never been confirmed.
Prisoners are seen behind a barbed wire fence at the time of Nazi German death camp Auschwitz-Birkenau’s liberation in 1945 in Nazi-occupied Poland, in this undated handout picture obtained by Reuters on January 19, 2020. Courtesy of Yad Vashem Archives/Handout via REUTERS ATTENTION EDITORS – THIS IMAGE WAS PROVIDED BY A THIRD PARTY.
Attempts to access federal files connected to the case repeatedly failed. Swiss authorities had sealed the documents until 2071, citing national security concerns and the protection of the extended Mengele family.
Historian Gérard Wettstein challenged the secrecy in court after his own request for access was denied in 2025. A crowdfunding campaign supporting the legal challenge raised 18,000 Swiss francs within days.
The Swiss Federal Intelligence Service then reversed its position, agreeing to provide access to the files.
Some historians believe the documents may reveal more about Switzerland’s wartime and post-war sensitivities than about Mengele himself. Sacha Zala, president of the Swiss Society for History, suggested the files could contain references to foreign intelligence agencies, including Israel’s Mossad, which actively pursued Nazi fugitives in the late 1950s and early 1960s.
Others argue the decades-long secrecy has only fueled conspiracy theories.
Jakob Tanner, who served on the Bergier Commission investigating Switzerland’s relationship with Nazi Germany, said the case reflects a longstanding tension between national security and historical transparency in Switzerland.
Mengele died in Brazil in 1979 under a false identity. DNA testing in 1992 confirmed his remains.
