On 27 September 1947 in Kraków, member of the Main Commission for the Investigation of German Crimes in Poland, Municipal Judge Dr. Stanisław Żmuda, acting at the written request of the First Prosecutor of the Supreme National Tribunal, this dated 25 April 1947, in accordance with the provisions of and procedure provided for under the Decree of 10 November 1945 (Journal of Laws of the Republic of Poland No. 51, item 293), in connection with Articles 254, 107, and 115 of the Code of Criminal Procedure, interviewed the former prisoner of the concentration camp in Auschwitz named below as a witness. The witness testified as follows:

Name and surname Ludwik Bas

Date and place of birth 18 December 1912 in Kraków

I was detained in the concentration camp in Auschwitz as political prisoner no. 3460 from 29 August 1940 to 18 January 1945. From the autumn of 1941 until the liquidation of the camp, I worked in the SS-Revier [SS hospital] as a nurse.

I know SS-Unterscharführer Hans Koch from the period of my detention in the camp from 1943, when he was employed in the SS-Revier [in the disinfecting unit] Desinfektor Kommando. The unit’s main task was to gas prisoners and, to a smaller extent, to degasify buildings, clothes and underclothes belonging both to SS men and to prisoners. This unit consisted of a few SS men who were directly subordinate to SS-Oberscharführer Klehr who, in turn, was subordinate to the camp doctor (Standortarzt). The task of gassing prisoners was carried out only by the SS men who made up the disinfecting unit. In the task of disinfecting buildings, clothes and underclothes, SS men selected a number of prisoners to help, but the gas remained solely at the SS men’s disposal.

I saw Koch almost every day as he regularly came to the SS-Revier building to receive orders and collect canned gas. Then, with a mask on his back, he drove off to Birkenau where, at the railway ramp, the arrival of the transports of prisoners was announced. I also saw him return from the gassing operations, especially those carried out at night, when he complained about being exhausted by the task of gassing prisoners. He had an incredible appearance and looked stunned. I talked to Koch and to other SS men from his unit about gassing. He consoled me by saying that the gassing wasn’t that terrible, that it lasted a short while and that sooner or later, we prisoners would also be subjected to it. I also saw him gassing prisoners in crematorium I and in the main camp.

During that period, I remember the gassings in the crematorium of the main camp were relatively rare and concerned small groups of prisoners brought in civilian clothes from the outside of the camp. I wish to note that at that time crematoria in Birkenau were already in operation. From the building of the SS-Revier, I was able to observe the area of the crematorium of the main camp. As I have already mentioned, I had the opportunity to see Koch gassing smaller groups of prisoners. In particular, I saw him pouring the gas through the openings in the roof of the crematorium. After the gassing, SS men put on gas masks and opened the door of the crematorium and the roof trapdoors to air the crematorium room. Of course, I could only watch these scenes very briefly because prisoners who were caught watching could be punished by death – a fate that befell a Jewish prisoner Moszkowicz, a French citizen of Polish descent, who was shot after he was found peeping through the window [at what was going on]. I often saw the SS men from the disinfecting unit collecting the gas cans stored in the building of the SS-Revier. I don’t know what words, if any, appeared on the cans. The camp’s main pharmacist was placed in charge of the gas can storeroom – first it was Krömer and, after his death, SS-Sturmbannführer Capesius and non-commissioned officer SS-Untersturmführer Gerber. In 1945 in Mauthausen, the latter was promoted to the rank of SS-Obersturmführer.

The whole SS disinfection unit, of which Hans Koch was a member, was privileged. Those who were part of the unit received what was known as Zulage – extra rations including milk, sausage, butter and vodka, which we prisoners brought them from SS-Küche (SS-kitchen) based on a special list signed by SS-Standorarzt, the camp’s chief doctor.

The following people can provide information regarding Hans Koch: the former prisoner Jan Sikorski, a pharmacist, living in Legnica at Jaworzyńska Street 5 (employed in the drug store of the SS-Revier); Stanisław Kondrach, living in Pruszków at Bolesława Prusa Street 45 and working as a chauffeur in the Polish Airlines in Warsaw based in the Roma building; Józef Nowacki living in Pruszków; Edward Pyź living in Kraków at J. Lea Street 7b (the student dormitory) and SS-Unterscharführer Karl Bar – Volksdeutscher, the former Polish citizen who was employed in the camp’s SS-Revier for a few years and who was sentenced by the Criminal Court in Wadowice to three years’ imprisonment.

At this the interview was concluded, read out and signed.