Us soldiers Nazi gold
US soldiers Nazi gold stored in a salt mine in Germany (Getty Images)

Two men claim to have discovered an armoured train car full of Nazi treasure but will keep its location secret until Polish authorities guarantee them a 10% cut.

Two residents of the town of Walbrzych in Lower Silesia told authorities of the discovery in a note in which they also outlined their offer, reported Polish news site daminfo.pl. Town authorities would not comment on the letter. Under Polish law, finders can keep up to 10% of the value of treasure.

Historians told local media that as the Red Army closed in on the city of Wroclaw, the Nazis loaded gold on to a train, which was sent in the direction of the Owl Mountains on the Polish/Czech border, where Walbrzych lies.

During the Second World War, the Nazis constructed a vast underground complex called Riese, or Giant, in the mountains. Some speculated the tunnels were intended as a residence for Adolf Hitler but experts argue they were intended to house armament factories as allied bombing of Germany intensified.