A secret operation involving ships, mini-subs and about 70 people took place between May and July last year but has only now come to light. Experts estimate that some of the haul, which includes dishes, jars and jugs, dates back to China's Ming dynasty, which lasted from 1368 to 1644.
The salvage team, thought to have been run by the government of Brunei, operated amid tight security with a Brunei navy boat keeping constant vigil.
'When any ship came close, a helicopter would fly out immediately and warn the ship to keep away,' engineer Gunawardena Nalin, who worked on the operation, told Singapore's Straits Times newspaper.
Mystery shrouds the discovery, but it is thought that the amount of treasure recovered is substantial. According to Mr Nalin, divers filled three or four boxes, each a cubic metre, daily during the three-month operation.
'Museum experts from France and Brunei were there all the time,' Mr Nalin added.
Some of the jade came in the form of uncut stones the size of a man's fist, he said.
'Just before the operation ended, some gold ingots were found. But the divers were told not to go back to that location. I think that another salvage team was sent back to get the gold later on.'
The secrecy surrounding the project makes valuation of the haul difficult. Most of those involved have declined to comment on the operation, and details have yet to reach international auction houses.
Many parts of the South China Sea and the nearby Malacca Straits are thought to be littered with ancient shipwrecks.
