The Swiss Federal Intelligence Service (FIS) has announced that it will grant access to a long-restricted intelligence file concerning Nazi war criminal Josef Mengele, marking a significant development in Switzerland’s ongoing reckoning with its historical links to the Second World War and Holocaust-era fugitives.
Known as the “Angel of Death”, Mengele was an SS officer and physician who carried out brutal and inhumane medical experiments on prisoners at the Auschwitz concentration camp. His crimes made him one of the most notorious Nazi figures to evade justice after 1945.
Following the collapse of Nazi Germany, Mengele escaped Europe through clandestine networks used by former Nazi officials and eventually settled in South America, living for years in Argentina, Paraguay, and Brazil while avoiding international prosecution. However, historical investigations later revealed that he had briefly returned to Europe as a tourist and had visited Switzerland during the post-war period.
The revelation of Mengele’s presence in Switzerland has long generated political and public interest. In recent years, several Swiss parliamentarians submitted motions demanding greater transparency regarding the Nazi fugitive’s activities on Swiss territory and the extent of Swiss authorities’ knowledge about him
The Swiss intelligence file on Mengele was previously examined by the Bergier Commission, an independent commission established by the Swiss government in 1996. The commission’s broader mandate was to investigate Switzerland’s conduct during the Second World War, including the handling by Swiss banks of dormant assets belonging to Holocaust victims and their families.
Despite the commission’s work, the Swiss government decided in December 2001 to impose additional restrictions on public access to the Mengele dossier. The documents were subsequently transferred to the Swiss Federal Archives and placed under an extended classification period.
Over the years, historians, journalists, and researchers repeatedly sought access to the file, arguing that disclosure was essential for understanding Switzerland’s post-war relationship with former Nazi fugitives. Yet the FIS consistently rejected those requests, including a refusal issued as recently as February 2026.
That refusal led to an appeal before the Swiss Federal Administrative Court, a legal challenge that appears to have contributed to the intelligence service’s recent reversal.
According to Swiss authorities, the decision to open the file stems from what the FIS described as a “new situation” following a fresh internal assessment of the case. While the intelligence service has not publicly detailed the precise reasons behind the reassessment, the move suggests a shift toward greater historical transparency.
The individual who appealed the original refusal will now be granted access to the documents under conditions and procedures that remain to be finalised. Swiss authorities indicated that the same framework will also apply to future requests for consultation of the file.
The opening of the Mengele dossier is likely to renew debate in Switzerland about the country’s wartime neutrality, post-war intelligence practices, and the degree to which former Nazi officials were able to move through or remain connected to Europe after the war.
For historians of the Holocaust and post-war Europe, the file could provide new insight into how one of history’s most infamous war criminals managed to travel internationally decades after the end of the war — and what Swiss authorities may have known at the time.
