Aron Czechowicz was a Polish Jew who arrived at the Treblinka Camp on 10 September 1942 from the Warsaw Ghetto, but managed to flee a few weeks later. He was interviewed by a Polish investigator on 11 October 1945. He claimed that he saw a gas-chamber building with three chambers, where the killing occurred by a Ukrainian auxiliary pouring some liquid from a canister through “three openings surrounded by a tube in the shape of a small chimney” located in the roof over each chamber, while an engine ran. This killing method and the associated introduction chimneys are otherwise undocumented, and are rejected as false and invented by all historians and other witnesses. This is probably a reflection of claims made about Zyklon-B gassings at Majdanek, Auschwitz and Stutthof.