He did all that under a false identity, for thirty months suffering cold, hunger, lice, illnesses, abuse, beatings and narrowly escaping death, producing reports which, shortly after his successful escape, he compiled into a comprehensive account of what the largest German concentration and death camp was. The intelligence he gathered went to the western Allies via the captain's Home Army commanders.

In 2017, the Pilecki Project Committee in Melbourne and the Institute of National Remembrance jointly released Report "W", containing the information Pilecki gathered as Auschwitz inmate, the yield of his sacrifice. The publication, based on and drawing from the resources stored at the IPN Archive, was subsequently translated into English by Eva Hussein, and in 2018, accompanied the exibit on the captain that toured Australia.

The IPN Archive holds many more materials on Witold Pilecki; of particular value to historians and interest to history lovers will be documents from the Stalinist period, such as search and interrogation reports, decisions to initiate investigations, underground records, files stolen from the Ministry of Public Security, or a decision to prosecute and the act of indictment.

The captain's life can be studied in greater detail on the IPN's dedicated website: https://biogramy.ipn.gov.pl/bio/wszystkie-biogramy/rotmistrz-witold-pileck/english-version/112337,Captain-Witold-Pilecki.html