A "significant" discovery linked to the search for a lost train filled with Nazi gold has been made in the Polish city of Walbrzych.

The city's Deputy Mayor, Zygmunt Nowaczyk, told a press conference that he had been contacted by lawyers for two men who claim to have found a lost stash of Nazi treasure somewhere in the city boundaries.

He said that he was not offered any direct proof, but said that the men are demanding a 10 per cent 'finder's fee' for discovering the goods inside, which could potentially be worth millions and would be Polish state property if found.

Now, it has emerged that something more solid linked to the lost train may have been found. Speaking to press, Nowaczyk said: "The city [of Walbrzych] is full of mysterious stories because of its history."

The city of Walbrzych in Poland, near to where the discovery has apparently been made (ADAM HAWALEJ/EPA)

"Now it is formal information - [we] have found something."

Since the end of the Second World War, there have been stories in the region of a lost train filled with Nazi gold being somewhere nearby.

As the story goes, when Soviet forces began to move through Poland to Berlin towards the end of the war, a train filled with gold and other treasures set off from Wroclaw to Walbrzych, in an effort to keep the riches out of Soviet hands.

Apparently, somewhere along this 50-mile journey, the train disappeared somewhere in the mountains around Walbrzych, and was never seen again.

An American soldier poses with thousands of gold rings taken from Jews in concentration camps

During the course of the war, Nazi Germany took some $550 million in gold from the governments of countries it occupied, including $223 million from Belgium and $193 million from the Netherlands.

The Nazis also took gold from individuals, particularly those who were victims of the holocaust. Concentration camp workers gathered gold rings, jewelery, watches, and even gold teeth from murdered victims, in efforts to shore up Germany's coffers.

Some of this gold was discovered by the allies at the end of the war, but much of it went unaccounted for, disappearing into banks and the hands of individuals in the chaos of Europe at the end of the war.

Huge sums in gold and currency were found by allied forces in the Heilbronn salt mines in Germany after the end of the war (National Archives/Getty Images)

However, if the men who claim to have found it are correct, some of this stash could be discovered.

The Telegraph reports the words of a local government press officer from the small city saying that a military train has been found, and Deputy Mayor Nowaczyk saying there was "formal information" relating to the lost train.

Around Walbrzych and the surrounding region, which is in the west of Poland and close to the German border, there are miles of tunnels, that were dug as part of 'Project Riese' by slave labourers when the area was part of Nazi Germany.

The purpose of the tunnels is unclear to this day, but some believe they may have been intended for use as secure military headquarters or weapons research facilities.

Stories and legends about the gold have often mentioned that the train lies in one of these tunnels, but some are now wondering if they could be the true resting places of the gold after all.

Speaking to The Telegraph, Arkadiusz Grudzien, a spokesman for Walbrzych council's legal office, says that the lawyer's letter does not give the exact location of the find, but says there is "no doubt" that it is within the local government's district.

He also says: "The train is of a military nature - there is no mention of valuables, just military equipment."