Most of the prisoners of war were released in 1948 and 1949, and in November 1949 the labour camp was converted to a prison. The facility, which became known under two names: Central Prison — Labour Centre in Warsaw () or Central Prison Warsaw II Gęsiówka (), did not de facto change its purpose, as the inmates were still producing building materials for Warsaw's reconstruction, and it still used forced labour, but instead of prisoners of war, common criminals and people accused by the of economic wrongdoings were sent there. According to Bogusław Kopka, 1,800 people died in the postwar prison; though an estimate of 1,180 victims also appears in the literature. The fact that the former Nazi camp was taken and run by the communist authorities was the main reason why the Chief Commission for the Investigation of German Crimes in Poland ceased its investigation into its history in 1947. The prison was closed in 1956 and was demolished in 1965. No element of the Nazi camp was preserved. As of 2022, the site is occupied by a garden square, residential buildings, and the building of the POLIN Museum of the History of Polish Jews. Inquiries It did not take long for the newly established Communist government in Poland to start analysing the events that happened in the camp's history. Already in May 1945, the Warsaw Circuit Commission for the Investigation of German Crimes in Poland launched a formal inquiry into the crimes committed in the Warsaw concentration camp. The premises were inspected by prosecutors several times, which yielded rich photographic documentation of the camp's buildings. On 15–25 September 1946, a total of 2180 kg of human corpses was exhumed and analysed (the corpses were then buried again in ); however, the exhumations did not cover the whole territory of the camp. In 1947, the inquiry was halted for the first time due to political considerations, as the former concentration camp had previously been taken over by the Ministry of Public Security, which converted it to a labour camp. It was only in 1974 that the investigation was continued on the request of the Central Office of the State Justice Administrations for the Investigation of National Socialist Crimes in Ludwigsburg, Germany; however, after two years, it was again suspended as the prosecutors deemed it impossible to retrieve more evidence in Poland. The investigation was once again opened in 1986,