On 13 September 1947 in Warsaw, a member of the Main Commission for the Investigation of German Crimes in Poland, Appellate Investigating Judge Jan Sehn, upon written request of the first prosecutor of the Supreme National Tribunal, this dated 25 April 1947 (file no. NTN 719/47), 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 Art. 254, 107, 115 of the Code of Criminal Procedure, interviewed the former inmate of the concentration camp in Auschwitz specified below as a witness, who testified as follows:
| Name and surname | Jerzy Pietrzyk |
| Age | 33 |
| Religious affiliation | Roman Catholic |
| Citizenship and nationality | Polish |
| Occupation | car mechanic |
| Place of residence | Warsaw, Grochów, Szaserów Street 105, flat 5 |
I was sent to Auschwitz with the first transport from Warsaw in 1940. I stayed there until 17 January 1945. I was given number 1761. At the time of my detention I met the following people:
Johannes Weber and Adolf Medefind, who were SS men. The latter held the rank of SS-Unterscharführer. I remember Weber from the time when he worked at a kitchen in the FKL [Frauenkonzentrationslager – women’s concentration camp], at the camp for men in Birkenau when it was located in the first section, and at the camp for Gypsies. He was one of the heads of the kitchen and as such he beat both men and women. In the camp for men he beat prisoners with whatever was within reach, very often with a spoon used for steering soup in a pot. He beat until the prisoners bled and collapsed. He was exceptionally sadistic towards the Gypsies, whom he called schwarze Juden [black Jews].
I met Medefind when he held the position of head of the so-called Verpflegungsmagazin [food warehouse]. I saw trucks driving off from the warehouse with margarine, sugar, and other high-quality products that were meant for prisoners. This is how the already scanty rations for the detainees were stolen. Medefind was involved in this practice, and he participated in it along with others, such as senior overseer of the kitchen, Werner Händler.
The report was read out. At this the hearing and the following report were concluded.