Image copyright Natonal Maritime Museaum Image caption The SS Central America sank to a depth of 2.2km (1.3 miles) in 1857 during a heavy storm while sailing from Panama to New York

A US deep-ocean exploration firm has recovered nearly 1,000 ounces of gold, worth $1.3m (£800,000), on a dive to a historic Atlantic Ocean shipwreck, company officials say.

The discovery has renewed speculation that gold worth tens of millions of dollars remains on the sunken ship.

The find confirmed that gold has not been taken from the vessel since 1991.

The SS Central America sank in 1857 killing 425 people, triggering one of the world's first financial crises.

Experts say the vessel - which was caught in a hurricane 257km (160 miles) off the South Carolina coast - was carrying 21 tonnes of gold which was intended to prop up the cash-strapped banks of New York. As a result, its loss created financial panic.

Image copyright Reuters Image caption Gold including this $20 Double Eagle coin that was recovered on the reconnaissance dive has gone on public display

Image copyright Reuters Image caption The SS Central America was carrying gold bars that were intended to prop up cash-strapped American banks

The gold found in the mid-April reconnaissance dive to the 85m (280ft) long side-wheel steamship is the first to be recovered from it in almost 25 years - but it is not clear exactly how much remains.

About $40-$50m (£24-£30m) was recovered during expeditions to the wreck in the late 1980s and early 1990s before legal disputes closed down the operation.

Announcing last month's successful reconnaissance dive, Odyssey Marine Exploration of Tampa, Florida, said there were substantial amounts of gold remaining.

Gold carried in person by passengers is believed to equal the value to the commercial cargo.

Recovered gold from the recent dive included five gold ingots and two $20 Double Eagle coins, an 1857 coin minted in San Francisco and an 1850 coin minted in Philadelphia.

US $20 Double Eagle coins fetch an average of $5,000 from collectors, a salvage officer told Reuters last week.

In March, Odyssey Marine Exploration won the rights to return to the shipwreck from a receiver.

The receiver had been appointed by an Ohio court to represent the first exploration company to survey the ship. This followed a decades-long court battle over rights to the treasure.

The ship was first located in 1988 by marine expert Thomas Thompson, who carried out the initial gold recovery operations.

But investors who backed the project are suing him, alleging he failed to hand over some of the proceeds.

Mr Thompson's whereabouts are currently unknown and a warrant was issued in 2012 for his arrest.