A Jewish organization has launched a database aimed at helping thousands of Holocaust survivors or their heirs regain property lost in Warsaw due to World War II, Star Tribune reports.

Under a new Polish law, people will have just six months to file claims for more than 2,600 properties in Warsaw after those properties are listed publicly in a newspaper or online, something expected to happen soon. Not all of the properties belonged to Jews, but it is believed that many of them did.

Claimants who fail to come forward by the deadline will relinquish their rights to the properties, with the city to assume permanent ownership of unclaimed properties.

“There is now a very limited opportunity for some kind of justice for people who suffered so much,” said Gideon Taylor, chair of operations for the World Jewish Restitution Organization, which created the database.

The new law, which entered into force in September, affects people who had property in Warsaw that they tried to reclaim after the war. At that time, the communist regime seized much of the prewar property, of Jews and non-Jews alike, making it impossible in practice for anyone to reclaim it until communism fell in 1989.

In the years since then, some original owners have reclaimed lost property in complicated legal proceedings, but it has been more difficult for the Jews who fled Poland and settled abroad.