[3] The Vrba–Wetzler report was widely disseminated by the Bratislava Working Group in April 1944, and with help of the Romanian diplomat Florian Manoliu, the report or a summary obtained from Moshe Krausz in Budapest reached—tragically with much delay—George Mantello (Mandl), El Salvador Embassy First Secretary in Switzerland, via Manoliu who brought it to Mantello.
The unprecedented events in Switzerland and possibly other considerations led to threats of retribution against Hungary's Regent Miklós Horthy by President Roosevelt, Winston Churchill and others.
This was one of the main factors which convinced Horthy to stop the Hungarian death camp transports.
[4] The full reports were published—with seven months delay—by the United States War Refugee Board on 26 November 1944 under the title The Extermination Camps of Auschwitz (Oświęcim) and Birkenau in Upper Silesia.
[1][5] They were submitted in evidence at the Nuremberg Trials as document number 022-L, and are held in the War Refugee Board archives in the Franklin D. Roosevelt Presidential Library and Museum in Hyde Park, New York.