On Wednesday, a stone monument was unveiled at the site with an inscription reading: “Unknown martyrs fallen for being Polish. 1939-44.”
IPN President Karol Nawrocki said at the ceremony, “The Germans decided to avoid the responsibility for the crimes they had committed."
He added that "the unburned remains" had been hidden in the ground "so that the crime would not see the light of day and no one could be held responsible”.
“The [Nazi] cover-up has failed because the IPN is determined to search for the victims and heroes of WWII and will never allow even one of them to be forgotten.”
Soldau was set up in 1939 in the town of Działdowo after the Germans invaded Poliand.
The camp housed around 30,000 inmates, 13,000 of whom were murdered.
The ashes found last month are the burnt remains of bodies dug up in 1944 by Jewish concentration camp inmates forced to act as slave labourers.
