US exploration firm Odyssey Marine, found the wreck of the SS Gairsoppa, a British cargo ship, sunk by a German U-boat in 1941.
Only one person from the 85-strong crew survived the torpedo attack as the ageing steamer tried to reach Ireland.
The vessel was on its way back to Britain from India when it ran low on fuel in stormy weather, and tried to divert to Galway harbour, but it was spotted and sunk by the German submarine.
Three members of the crew survived in a lifeboat and reached the Cornish coast two weeks later, but two died trying to get ashore.
Second officer Richard Ayres reached shore at the Lizard lighthouse in Cornwall 13 days after the sinking.
He was made an MBE for his efforts in trying to save his fellow sailors, and lived until 1992.
Odyssey Marine will get to retain 80% of the cargo’s value under the terms of a contract with the United Kingdom Department for Transport.
The wreck is 500 kilometres off the Irish coast at a massive depth of 4,700m below the North Atlantic.
SS Gairsoppa settled upright on the seabed with its cargo holds open, which means remote-controlled robotic submarines should be able to retrieve the bullion.