Nowodowski, Dawid
Dawid Nowodowski was one of the first witnesses to testify about the Treblinka Camp. He was deported there on 18 August 1942, but managed to escape after just a few days. On 28 August 1942, hence before any propaganda or alleged witness accounts about this camp started spreading, he wrote a Report of the stay at the extermination camp of Treblinka.
However, it does not contain any reference to mass extermination or killing chambers. The only terse and uninformative allusion to it reads: 2 executions after 15 minutes up to 40 minutes.
(See Mattogno 2021e, p. 121.)