Sonderaktion 1005 (German pronunciation: [zɔndɐakt͡sjoːn aɪ̯ntaʊ̯zəntfʏnf], 'Special Action 1005'), also called Aktion 1005 or Enterdungsaktion (German pronunciation: [ɛntɐdʊŋsakt͡sjoːn], 'Exhumation Action'), was a top-secret Nazi operation conducted from June 1942 to late 1944. The goal of the project was to hide or destroy any evidence of the mass murder that had taken place under Operation Reinhard, the attempted (and largelysuccessful) extermination of all Jews in the General Government occupied zone of Poland. Groups of Sonderkommando prisoners, officially called Leichenkommandos ("corpse units"), were forced to exhume mass graves and burn the bodies; inmates were often put in chains to prevent them from escaping.
The project was put in place to destroy evidence of the genocide that had been committed by the Order Police battalions and Einsatzgruppen, the German death squads who murdered millions, including more than one million Jews, Roma and Slavs. The Aktion was overseen by selected squads of the Sicherheitsdienst (SD) and the uniformed Order Police.