The remains were found on the former premises of the Warsaw III Prison, a Stalinist facility also known as Toledo.

The prison was active between 1944 and 1956 - three years after Stalin's death - in Warsaw's North Praga neighbourhood.

Political prisoners who were considered a threat to the Stalinist regime and new communist authorities were also sent to Toledo.

The prison was considered by prisoners to be the harshest.

The Prison was later handed over to the Polish Department of Security (UB), the chief secret service of the communist regime in Poland.

Since September 1944, the prison played a role in the extermination of Poles striving for independence from their Soviet occupiers.

"Full archaeological search in the area of the former 'Toledo' Prison will be conducted by the IPN’s Office of Search and Identification in the coming weeks."