Treasure hunters have begun digging for a fabled Nazi-era golden train in south-west Poland despite the results of a geological survey which held there could be no train.

Last year we reported that amateur treasure hunters claimed to have discovered an armoured train filled with Nazi loot, buried deep under ground in a railway embankment near the city of Wałbrzych. Piotr Koper from Poland and Andreas Richter from Germany believe the train departed Wrocław bound for a secret command centre built by Hitler. As Soviet and Allied forces entered Poland in the final days of WWII the train was sealed in an underground network of tunnels. It is thought to contain stolen art, jewels, gold and weapons.

On the back of the explorers’ claim, experts from Krakow’s AGH University of Science and Technology conducted an independent study of the site. With the aid of magnetic field detectors, thermal imaging cameras and radars the scientists reached the conclusion that no trace of a train existed. Their findings were consistent with the view of historians who point to an absence of documentary evidence relating to the train.

Nevertheless, a spokesman for Koper and Richter has said the men remain confident they will find it. “We have to find a railway track, probably the entrance to a railway tunnel and, if the tunnel exists, there should be a train there,” Andrzej Gaik told reporters. Preliminary work carried out at the site over the weekend using ground-penetrating radar was said to have yielded “extremely promising” results. Excavations using heavy equipment began yesterday (16 August) and the explorers expect to confirm the existence of the gold train within three to four days. The entire dig could take up to 10 days.

It’s not a needle in a haystack. If it’s there, we will find it,” Gaik said.