This seems to have been presented in a book by Shelly Shapiro "Truth Prevails: Demolishing Holocaust Denial" but snippets can be found on the web. I provide a couple (links can be found by googling)
From the testimony of SS-Unterscharfuehrer Wilhelm Bahr in his trial at Hamburg
[Quoted in "Truth Prevails", ISBN 1-879437-00-7, p. 99].
Q: Is it correct that you have gassed 200 Russian POW's with Zyklon-B?
A: Yes, on orders.
Q: Where did you do that?
A: In Neuengamme [concentration camp].
Q: On whose order?
A: The local doctor, Dr. Von Bergmann.
Q: With what gas?
A: With Prussic acid [another name for Zyklon-B].
Q: How long did the Russians take to die?
A: I do not know. I only obeyed orders.
Q: How long did it take to gas the Russians?
A: I returned after two hours and they were all dead.
Q: For what purpose did you go away?
A: That was during lunch hour.
Q: You left for your lunch and came back afterwards?
Q: Were they dead when you came back?
Q: Did you look at their bodies?
A: Yes, because I had to load them.
Q: Why did you apply the gas to the Russians?
A: I only had orders to pour in the gas and I do not know anything about it.
Perhaps the most thorough description of the gassing process was provided in 1946 by the British
Military Tribunal in Hamburg. A report on gas chamber execution, prepared by ex-medical orderly
and Unterscharfuhrer Wilhelm Bahr, was read there during Bahr’s cross-examination. Bahr had
“. … with an iron rod and hammer they open a couple of harmless looking tin
boxes, the directions read “Cyclon[sic], vermin destroyer. Warning, Poisonous.”
The boxes, are filled with small pellets which look like blue peas. As soon as the
box is opened the contents are shaken out through and aperture in the roof. Then
another box is emptied in the next aperture, and so on. And in each case the cover
is carefully replaced on the aperture… Cyclon works quickly, it consists of a
cyanic acid compound in a modified form. When the pellets are shaken out of the
box they give off prussic acid gas….After about two minutes the shrieks die down
and change to low moaning. Most of the men have already lost consciousness.
After a further two minutes….it is all over. Deadly quiet reigns….The corpses are
piled together, their mouths stretch open….It is difficult to heave the interlaced
corpses out of the chamber as the gas is stiffening all their limbs.” 1
Quite an accurate version of what we understand to happen at Auschwitz. Does anyone know much about a gas chamber at Neuengamme? Real or an improvised facility or just someone forced into false confession? Or anything about Wilhelm Bahr?
Update: I also see that Wilhelm Bahr was a witness in the Bruno Tesch case, so I am not sure if Shelley Shapiro has taken her bits of testimony from there or if there was a trial dedicated to Wilhelm Bahr.