Alfréd Wetzler (10 May 1918 - 1988), who later wrote under the alias Jozef Lánik, was a Slovak Jew, and one of a very small number of Jews known to have escaped from the Auschwitz death camp during the Holocaust. Wetzler is known for the report that he and his fellow escapee, Rudolf Vrba, compiled about the inner workings of the Auschwitz camp - a ground plan of the camp, construction details of the gas chambers, crematoriums and, most convincingly, a label from a canister of Zyklon gas. The 32-page Vrba-Wetzler report, as it became known, was the first detailed report about Auschwitz to reach the West that the Allies regarded as credible. The evidence eventually led to the bombing of several government buildings in Hungary, killing Nazi officials who were instrumental in the railway deportations of Jews to Auschwitz. The deportations halted, saving up to 120,000 Hungarian Jews.
Wetzler was sent to the Birkenau (Auschwitz II) camp in 1942 and escaped from it with Vrba on 7 April 1944. Using the pen name Jozef Lanik, he wrote up the story of his experiences in Slovak as Auschwitz, Tomb of Four Million People, a factual account of the Vrba-Wetzler report, and later a fictionalized account called What Dante Did Not See.
The historian Sir Martin Gilbert said: "Alfred Wetzler was a true hero. His escape from Auschwitz, and the report he helped compile, telling for the first time the truth about the camp as a place of mass murder, led directly to saving the lives of thousands of Jews - the Jews of Budapest who were about to be deported to their deaths. No other single act in the Second World War saved so many Jews from the fate that Hitler had determined for them."
Alfréd Wetzler died in Slovakia in 1988.