On 18 October 1945, in Sokołów Podlaski, Judge Z. Łukaszkiewicz 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 | Mieczysław Laskowski |
| Age | 36 |
| Names of parents | Stanisław |
| Place of residence | Sokołów, railway station |
| Occupation | train dispatcher with Polish State Railways |
| Religious affiliation | Roman-Catholic |
| Criminal record | none |
From the summer of 1941 until the arrival of the Red Army, I worked at the railway station in Bielany, located on the railway line between Siedlce and Sokołów. As far as I can remember, from July 1942 onwards transports bound for Treblinka started to go through the Bielany station. There were between one and five transports running daily. It continued like this approximately until New Year’s Day 1943.
I can firmly say that I am not exaggerating when I state that there were two transports daily on average in that period. Each transport consisted of 50–60 wagons, and each wagon (judging by the inscriptions in chalk) contained from 100 to 120 people.
The trains were escorted by Ukrainians and SS-men, who killed many people trying to get out of the wagons. After the passing of such a transport, there were usually a few corpses lying next to the railway tracks. The wounded were finished off by the German Gendarmerie from Sokołów, who went on patrol along the tracks especially for that purpose.
I also know that there were transports of Jews coming from abroad. I especially remember the transport from Bulgaria and Greece. If I am not mistaken, I also heard about transports from Belgium and Romania.
As for the method of exterminating people in the Treblinka camp, I do not know anything.
The witness interview report was read out to the witness and signed by him.