COLUMBIA, South Carolina (AP) — Three Americans have been found guilty of bilking thousands of investors out of more than $80 million.

A federal jury in South Carolina of four men and eight women deliberated for less than four hours on Friday before finding Timothy McQueen, Joseph Brunson and Tony Pough guilty of nearly 60 charges each. The charges included conspiracy, mail fraud, and money laundering.

The men called themselves the "3 Hebrew Boys" after the biblical tale of men who survived an inferno because of their faith.

The three showed no reaction as the 15-minute verdict was read. Later, the same jury ordered the men to forfeit $82 million, the maximum sought by authorities. They could also face decades in prison.

The three preyed on debt-plagued investors to ensnare them in a Ponzi scheme, offering what they termed a ministry that would pay off their mortgages, car loans, or other debts, or pay dividends for life. Despite a lack of financial training, they convinced at least 7,000 people — starting in late 2004 — that they knew the secret of how to make money on the foreign exchange market, though they invested less than 0.01 percent of their collections there, prosecutors said.

Their operation was shut down in May 2007, and $17 million was seized.

"If it sounds too good to be true, it probably isn't true," said Assistant US Attorney Mark Moore.

Referencing Bernard Madoff's multibillion-dollar fraud as an example of a Ponzi scheme, he added, "At least he didn't claim he came in the name of God and market it that way." Investors came from two dozen states and soldiers serving in Iraq.

Defence attorneys argued the three intended to honour the contracts or pay the money back. The three paid out more than $22 million to early investors, including several hundred debts paid off.

"It's a debt-elimination programme. That was the intent," said Brunson's lawyer, Mike Duncan. He called the $801 million prosecutors say their clients contractually owed "cartoon math".

"They never made that promise," Duncan said.

Prosecutors allege the three spent more than $25 million on themselves for luxuries including three condos in suburban Atlanta, luxury suites at football stadiums, a Gulfstream jet, limousines, a motorcoach and 20 acres in Orangeburg.

But the defence argued those were investments, and their plans included renting out the vehicles and operating a charter jet service.

If investors knew up front their plans for the money, they never would have mailed in their money, said Assistant US Attorney Winston Holliday.

"A waiver doesn't count when someone steals money from you," he said. "This is not a case about risk. It's about defrauding you. All these presentations about money going into the (foreign exchange) market — lies — that's not risk."