On 18 September 1947 in Toruń, District Investigative Judge Józef Becker, Investigative Judge of the District Court in Toruń, with its seat in Toruń, interviewed the person specified below as an unsworn witness. Having been advised of the criminal liability for making false declarations and of the wording of art. 107 of the Code of Criminal Procedure, the witness testified as follows:
| Name and surname | Leon Mackiewicz |
| Age | 32 |
| Parents’ names | Władysław and Anna |
| Place of residence | Toruń, [...] |
| Occupation | director of the regional branch of the Supply Fund |
| Religious affiliation | Roman Catholic |
| Criminal record | none |
| Relationship to the parties | none |
I was interned at the Auschwitz concentration camp between 20 August 1940 and October 1944 as a political prisoner. Subsequently, I was evacuated to other camps in the German Reich. Out of the persons whose photographs have been now presented to me, I recognize everybody, i.e. Otto Lätsch, Karol Seufert, and Kurt Müller. As regards the former two, i.e. Otto Lätsch and Karol Seufert, I cannot say much about them from my own observations, since I had no direct contact with them. Otto Lätsch, as I can recall, was Blockführer at block 11, I believe, and the same goes for Karol Seufert, who, as far as I remember, was also a Blockführer.
Particular criminal deeds against camp prisoners perpetrated by the above persons are unknown to me. I had more direct contact with Kurt Müller, whom I met in 1943, on the grounds of the Auschwitz concentration camp, where he served as Blockführer, including for some time at block 11, where he was promoted to the rank of Unterscharführer. After some time, he became the so-called Arbeitsdiensführer [work service leader], and he discharged this function for the remainder of my time at the camp. I shall describe Müller as a “rigorous and ruthless martinet”, who at the same time was not characterized by brutality or particular sadistic tendencies. From my own observations, I can tell that he participated in the selections of the Auschwitz Jews earmarked for “gas”. Otherwise, I am not familiar with any particular instances of Müller’s torturing prisoners.
This is all I know regarding the case.
The report was read out before it was signed.