Erwin Bartel was a Polish Auschwitz inmate between 5 June 1941 and 26 October 1944, where he worked as a clerk in the Political Department under Hans Stark and Maximilian Grabner. In a deposition of 27 August 1947 in preparation for the Polish show trial against Grabner and other former Auschwitz staff members, Bartel merely confirmed that he saw Grabner on the roof of Crematorium I observing a homicidal gassing through one of the Zyklon-B introduction hatches. However, as the head of the Political Department, Grabner is unlikely to have crawled onto the roof, and even less likely to have jeopardized his life or that of others by keeping those alleged hatches open in order to observe what was going on inside, allowing Zyklon B fumes to reach him in the process. For observational purposes, a spyhole in the door is said to have existed, if we follow the orthodox narrative. Hence, this terse statement was clearly an attempt to frame his former boss Grabner.
In preparation for the Frankfurt Auschwitz show trial, Bartel made another deposition in the late 1950s, but this time he targeted Hans Stark, who was among the defendants of that trial. Bartel merely stated that Stark was very interested in these gassings and saw him participate in them. He also claimed that Stark was responsible for the boxes of Zyklon-B cans, which were allegedly kept in the corridor next to the office where Bartel and Stark worked. However, anything connected with fumigations – Zyklon B, gas masks, test kits etc. – was the responsibility of the SS garrison physician and was stored in the SS infirmary. Furthermore, due to its dangerous nature, Zyklon B was certainly never kept in a corridor of a pencil-pusher office. (For more details, see Mattogno 2016c, pp. 35f.)