An interesting story appeared recently in the UK Independent about Alfred Wetzler. Wetzler escaped from Auschwitz and took evidence with him that provided the basis for saving thousands of lives:
A dramatic first-hand account of how a prisoner managed to escape from Nazi Germany’s most notorious death camp and help save more than 120,000 Jews from slaughter is to be told for the first time to an English-speaking audience…
It was in the spring of 1944, with the assistance of other prisoners, that the pair managed to escape… The two men had also smuggled out damning evidence – 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 dossier, later known as the Auschwitz Protocol, was telegrammed to Churchill when the pair finally made it back to Slovakia. 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.