Swiss intelligence service publishes Josef Mengele dossier

The Federal Intelligence Service has published its historical dossier on Nazi war criminal Josef Mengele after a legal dispute with a historian, SRF reported on Thursday. The agency has also changed its previously restrictive policy and made the files available online.

Mengele, an SS doctor at the Auschwitz Birkenau concentration camp who carried out cruel medical experiments on people, remains the subject of official investigations. The dossier was originally compiled by the police service of the Office of the Attorney General, a predecessor of the Federal Intelligence Service, and transferred to the Federal Archives in 2001.

Because the files were subject to an extended protection period lasting until the end of 2071, the intelligence service had repeatedly rejected requests to view them, most recently in February 2026.

Historian Gérard Wettstein challenged the latest refusal before the Federal Administrative Court. During the proceedings, it emerged that the Mengele dossier was covered by a 2001 Federal Council decision concerning the files of the Bergier Commission, the Independent Commission of Experts Switzerland Second World War. That decision requires a particularly open policy on access.

The dossier had not been marked accordingly in the archives, meaning the Federal Intelligence Service had previously been unaware of this classification. In May 2026, the agency announced that it would reconsider the matter. It has now released the dossier online instead of arranging individual access at its premises.

Some passages have been redacted, although the intelligence service said the redactions had been kept to a minimum. They protect personal data belonging to former and current federal administration employees with links to the agency, information covered by legal source protection, and private third parties.

Wettstein said he was disappointed that the dossier had been published online with redactions rather than being made available to researchers without them. He said secrecy more than 80 years after the end of the war was incompatible with academic freedom and damaged Switzerland’s reputation. He also pointed to Mengele’s alleged visits to Swiss holiday resorts in the 1950s and said the redactions created the impression of unprofessional surveillance.

Wettstein said he would appeal to the Federal Administrative Court. The Federal Intelligence Service said the course of events could still be fully reconstructed despite the redactions. The original document remains unchanged in the Federal Archives.

The case has prompted the intelligence service to undertake a general review of its archive policy. The agency said it was fundamentally examining its previously very cautious approach to releasing archival documents, in cooperation with the Federal Archives. The published dossier can be downloaded from the agency’s website.