CHARLESTON (REUTERS) - A deep-ocean exploration company in Florida says it has recovered nearly 1,000 ounces of gold, worth US$1.3 million (S$1.6 million) at current gold prices, on a reconnaissance dive to an historic Atlantic Ocean shipwreck.

The dive confirmed that the ship had not been disturbed since 1991 when another company stopped recovery work, Tampa-based Odyssey Marine Exploration, announced on Monday. The ship's sinking in 1857 with 21 tons of gold aboard in a hurricane off the coast of South Carolina sparked a US banking panic.

Recovered gold included five gold ingots and two $20 Double Eagle coins, an 1857 coin minted in San Francisco and an 1850 coin minted in Philadelphia. The gold ingots were stamped with the manufacturer's "assay-mark" and weigh from 96.5 to 313.5 troy ounces.

US $20 Double Eagle coins fetch an average of US$5,000 from collectors, Odyssey's chief operating officer Mark Gordon told Reuters last week.

In March, Odyssey won the rights to return to the shipwreck from a receiver who had been appointed by an Ohio court to represent the ship's first exploration company after a decades-long court battle over rights to the treasure and return for investors

More than US$40 million in gold was recovered by the original team led by Tommy Thompson, an Ohio engineer who discovered the shipwreck in 1988 using sonar and robotic technology he developed.

The recovery efforts were derailed by lawsuits and investors accused him of failing to pay them. He has been considered a fugitive since 2012 when he failed to appear in court for a hearing.

Only about 5 per cent of the shipwreck site was explored in the late 1980s, Gordon said.

The two-hour reconnaissance dive in mid-April took place as the company's research vessel, Odyssey Explorer, was traveling from the UK to Charleston, the company revealed on Monday.

Odyssey Explorer left Charleston recently to begin the bulk of recovery work at the shipwreck 160 miles off the South Carolina coast and 2.2 kilometers deep.

The 85 meters sidewheel steamship carried as much as 21 tons of gold ingots, freshly minted gold coins and raw gold from the California mines, as well as the personal wealth and belongings of its 477 passengers, most of whom were lost when the ship sank.

Historians say the loss of the gold caused a banking panic that contributed to a larger US economic crisis, called the Panic of 1857, that lasted several years.