Chief Commission for the Prosecution of Crimes against the Polish Nation

Chief Commission for the Prosecution of Crimes against the Polish Nation (Główna Komisja Ścigania Zbrodni przeciwko Narodowi Polskiemu) is an investigating department of the IPN and simultaneously a specialised part of the public prosecutor's office of the Republic of Poland. It conducts penal proceedings concerning the Nazi and Communist crimes ("actions performed by the officers of the communist state between September 17, 1939 and July 31, 1990 which consisted in applying reprisals or other forms of violating human rights in relation to individuals or groups of people" Art. 2 Act on the Institute) and other crimes which are classified as crimes against peace, war crimes and crimes against humanity committed on Polish citizens and on people of Polish nationality who were citizens of other countries, between 1 September 1939 and the end of 1990.

The Chief Commission also investigates "any person who, without being authorised, destroys, hides, damages, removes or modifies the contents of the documents or information records" as well as "refrains from transferring them, impedes their transfer or thwarts it" (Art. 54 Act on the Institute). Finally the Chief Commission is responsible for reviewing and prosecuting cases in which a person publicly and contrary to the facts denies crimes (Art. 55 Act on the Institute), such as is in cases of  "Holocaust Denial" ("Kłamstwo oświęcimskie").

The Chief Commission is continuing the work of the Chief Commission for the Investigation of German Crimes in Poland, which (under various names) existed since 1945 and was incorporated into IPN at the moment of its establishment in the year 2000. From the beginning of the functioning of the IPN's investigative department, i.e. from August 2000, prosecutors took over the entire investigative and archival resources of the former Chief Commission for the Investigation of German Crimes in Poland, and began their investigations. Consequently, since the beginning of the IPN prosecutors have conducted over 10,000 investigations, during which they have questioned more than 80 thousand people as witnesses.

One of the most important investigations include the initiated and conducted since 2004 investigation into the Katyń massacre, regarding murdering more than 22 thousand officers, policemen, political prisoners and prisoners of war as well as other state officials in Katyń, Tver , Kharkov and other sites, under a resolution of the highest Soviet authorities of 5 March 1940. This investigation includes seeking and interrogating thousands of people who are legal successors of the victims. Also, archival queries were carried out in Ukraine, Belarus, Great Britain, the United States and other countries. The investigation into the Katyń massacre as well as other legal proceedings conducted by the IPN prosecutors (e.g. in the case of crimes committed by officers of the Third Reich in 1939-1945, Ukrainian nationalists in 1939-1947 or the Communist crimes that were perpetrated until the end of 1989) significantly contribute to learning about the tragic history of Poland.

Other significant investigations carried out by the prosecutors of IPN include the Jedwabne pogrom, where approximately 250 Jews were killed by Polish peasants, or the investigation into the Augustów roundup, which was a post-war crime committed by Soviet soldiers on Polish independence fighters from the Home Army (AK), who have surrendered after fighting the Germans in local woods – a crime named by many as "little Katyń".