The Swiss federal intelligence service has released a previously classified 200-page dossier on Josef Mengele, the Nazi doctor infamously known as the “Angel of Death” for his role in conducting brutal medical experiments at Auschwitz during World War II. The publication comes after a successful legal challenge by historian Gérard Wettstein, who contested the government’s decision to keep the documents sealed until 2071.

Mengele, who served at the Auschwitz extermination camp in Nazi-occupied Poland, was involved in atrocities that contributed to the deaths of approximately 1.1 million prisoners, nearly one million of whom were Jewish. After the war, he evaded capture by fleeing to Latin America, where he lived covertly until his death in 1979 by drowning off the coast of Brazil.

The released dossier contains intelligence suggesting that Mengele might have returned to Switzerland at some point after escaping Germany or was possibly attempting to enter the country using a false identity. Swiss authorities had cited security concerns as the basis for the decades-long classification of these files.

The disclosure of the documents marks a significant development in the ongoing efforts to shed light on postwar movements of Nazi officials and the extent of their concealment across Europe. The release follows a rare judicial decision allowing greater transparency into intelligence archives that have been withheld to protect state security interests.