The restored Amber Room in the St
The restored Amber Room in the Catherine Palace, St Petersburg, was unveiled the 2003. The original has never been found. Getty Images

A group of treasure hunters have been given the OK for an expedition in a series of caves in Germany as part of the hunt for Hilter's most valuable loot, lost since the second world war. 73-year-old Leonhard Blume, 67-year-old Günter Eckardt, and 71-year-old Peter Lohr think that within the caves near Dresden they will find Russia's famous Amber Room.

The Amber Room was adorned with gold, amber and jewels and first constructed in the 1700s in Prussia, according to the Smithsonian magazine. It was given to Russia's Peter the Great in 1716 to celebrate peace between Russia and Prussia.

When Nazi leader Adolf Hitler sent troops east during the second world war, they looted treasures along the way - though curators tried to disguise the room, Nazi soldiers took it apart and shipped it to Königsberg, present day Kaliningrad, where it was set up in a castle.

What happened next is still unknown. Some think the room was destroyed in the bombings that prefaced Soviet forces making their way across Germany, while others think the room had already been moved by then.

Peter Lohr used radar imaging to detect what he says are bunkers underground in Prince's Cave in the Hartenstein hills, the Mail Online reported. He also said the imaging showed booby traps. "The hideout is underground, above the railway line, where in April 1945 a train from Königsberg was stopped," Lohr told the site.

The caves were said to have been used by Nazi scientists but no-one knows what went on there - it could be the resting place of a room estimated to be worth £200m.

Though the original remains missing, a reconstruction was started in 1979 at the Catherine Palace and later opened in 2003 by Russian President Vladimir Putin and German Chancellor Gerhard Schröder on the 300th anniversary of the founding of St. Petersburg.