(JTA) — With evidence mounting that a Nazi train loaded with millions of dollars worth of plundered items has been found in Poland, the World Jewish Congress urged the Polish government to ensure any goods stolen from Jews be returned to their legitimate owners or their heirs.

Last week, Polish Deputy Culture Minister Piotr Zuchowski announced he has seen a ground-penetrating radar image indicating that the train, which two unidentified individuals claimed to locate earlier this month, likely exists. Soon after the announcement, World Jewish Congress CEO Robert Singer said in a statement, “To the extent that any items now being discovered in Poland may have been stolen from Jews before they were sent to death, concentration or forced labor camps, it is essential that every measure is taken to return the property to its rightful owners or to their heirs.” The statement added, “If no such survivors or heirs can be found, any gold or other property that is found to have belonged to Jewish families or businesses must now inure to the benefit of Polish Jewish survivors who unfortunately have never been adequately compensated by Poland for the unspeakable suffering they endured and their catastrophic economic losses in the Holocaust.”

The train is believed to be one that reportedly disappeared in 1945 loaded with gold, gems, art and guns bound for Berlin, one of several trains the Nazis used in an attempt to save their war plunder from the advancing Allies. According to local lore, the train vanished after entering a network of tunnels under the Owl Mountains. Two men, one German and one Polish, approached government officials in Poland’s southwestern district of Walbrzych earlier this month, claiming to have found the train but saying they would not reveal its location until they were guaranteed a 10 percent finder’s fee.

At a press conference Friday, Zuchowski said he was “more than 99 percent certain that this train exists,” according to The Associated Press. Zuchowski also said the two men who claim to have found the train learned of its location from a dying individual who had been involved in transporting the train in 1945. “If it is confirmed that the train is carrying valuable items, the finders can expect a 10 percent finder’s fee, either in the form of a reward from the ministry or from the owners of the property,” Zuchowski said.

He said any recovered valuables whose original owners can be identified would have their property restored to them.