Warsaw, 12 October 1948. A member of the District Commission for the Investigation of German Crimes, Judge Halina Wereńko, interviewed the person specified below as a witness, without swearing him in. Having been advised of the criminal liability for making false declarations, the witness testified as follows:
| Forename and surname | Kazimierz Kostrzewa |
| Names of parents | Szczepan and Julianna, née Werclich |
| Date of birth | 8 December 1922 in Białobrzegi |
| Religious affiliation | Roman-Catholic |
| Education | elementary school |
| State affiliation and nationality | Polish |
| Place of residence | Białobrzegi, Nieporęt county |
| Occupation | farmer |
Approximately in the middle of September, 1941, the first transport of Soviet prisoners of war arrived at the barracks in Białobrzegi; this camp was in operation until the Warsaw Uprising in 1944. In September 1941, I worked in the camp on the construction of huts. At that time I saw the first transport arrive. A large group of prisoners arrived; there may have been up to 2,000 people. They were put in the stable and remained there until the huts had been erected. Working on the construction of the huts, I could see that the prisoners were very badly treated; they were beaten and harassed during the distribution of meals. Every day, they received about half a liter of soup and a small piece of bread. In October 1941, I saw a Soviet prisoner picking and eating linden leaves. He was then shot by a German soldier. I saw a transport of prisoners being escorted from the Wieliszew railway station to the camp.
It was in January or maybe February, 1942. Those prisoners who were weak or could not keep up with the marching group were shot by the German soldiers. I saw them finish two prisoners off; on the following day, I saw seven corpses lying next to the road. At first, thedeath rate in the camp was very high; I often saw 200 corpses being taken away in one transport; later, it decreased a little.
At this the report was concluded and read out.