High radiation levels found in an Austrian town indicate it may have been a spot for Nazi nuclear testing.

The town of St. Georgen an der Gusen had long been rumored to have been home to a buried Nazi bunker nearby where nuclear weapons testing took place during WWII.

Last week, the 75-acre underground complex was dug up, adding further fuel to the suspicions.

Austrian filmmaker Andreas Sulzer led the dig team, and he told the Times of Israel the site was “likely the biggest secret weapons production facility of the Third Reich.”

And the Daily Mail is reporting the site likely benefited from forced labor at the Mauthausen-Gusen concentration camp.

“Up to 320,000 inmates are said to have died because of the brutal conditions in the subterranean labyrinth,” Sulzer added.

SS Gen. Hans Kammler is believed to have headed the weapons facility, which is near the B8 Bergkristall factory. At B8 Bergkristall, the first working jet-powered fighter was made.

Rainer Karlsch, a historian working with Sulzer, told media: “The SS leadership . . . aspired to create a combination of missiles and weapons of mass destruction. They wanted to equip the A4 [a variant of the V-2] missile, or more advanced rockets, with poison gas, radioactive material or nuclear warheads.”