LONDON — When two men claimed to have found a mysterious train filled with Nazi gold last fall in Poland, it all seemed too spectacular to be true. Skepticism of the alleged finding quickly overtook the initial enthusiasm.

This week, we may finally find out whether the Nazi train has indeed been found.

One year after Germans Piotr Koper and Andreas Richter claimed to have traced the train, they and a team of 33 researchers started digging for it Tuesday morning. A report they worked on found that soil anomalies may hint at the train's existence, but another study — by the AGH University of Science and Technology in Krakow, Poland — found no evidence for that. The latter study, though, concluded that a tunnel may be at the location where Koper and Richter will put their theory to the test.

"The train is not a needle in the haystack; if there is one, we will find it," Andrzej Gaik, a spokesman for the search committee, told the Agence France-Presse news agency. The committee consists of volunteers but no Polish officials, who refrained from participating in the search efforts.

Gaik remains hopeful: "If we find a tunnel, then that is also a success. Maybe the train is hidden inside that tunnel." The privately funded effort will be streamed live online and could be completed within two days. Using special equipment, the search team is planning to drill three holes into the ground.

Poland's chief curator of monuments, who is not part of the search committee, was quoted as saying Tuesday that he was optimistic the search efforts would be successful. "We're talking about a train that is supposed to be more than 100 meters long," he said.

The story of a Nazi-era train with valuable art, gems and gold that disappeared at the end of World War II in 1945 has circulated for decades. It is thought to have been last seen near the city of Wroclaw, which today is part of Poland, but researchers and hunters have been unable to find the tunnel complex where it is thought to be hidden.

Speaking to WorldViews on Monday, research committee member Christel Focken acknowledged that it was uncertain whether the team would find any gold. "Our geo-radar images show that there is a train with vehicles on it," Focken said, suggesting that the vehicles could be tanks.

The tunnel system carried the name "Giant" ("Riese"), which indicates the dimensions of the underground network. The Riese tunnel network was also supposed to house a bunker for Adolf Hitler, but there are varying accounts of whether construction was ever finished. The Hitler bunker was never found, but Focken and her colleagues hope that the tunnel might lead to it.

The Polish news site Wiadomosci Walbrzyskie reported last year that up to 300 tons of gold could be hidden on the long-lost train, if it exists.

The history of Nazi gold has been well documented. Using jewelry from Jews and other prisoners who had been sent to concentration camps, the Nazis melted the metal into ingots. When Allied forces advanced at the end of the war, the Nazis transported that gold back to Germany amid fears that it might fall into Soviet hands. Experts say that not all of it has been found.

Still, researchers have remained wary of those claims. There is no evidence that the train ever existed, although locals have passed on the story since 1945, when the war ended.

Despite not participating in the search, local officials took the claims of the finding seriously. The Reuters news agency quoted local official Marika Tokarska as saying last August: “Lawyers, the army, the police and the fire brigade are dealing with this. ... The area has never been excavated before, and we don’t know what we might find.”

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