According to prosecutors the two Liberians had sold nearly all of World Vision's food aid; auditors said a third of it was allocated to towns that did not exist.

World Vision administered a programme funded by the US Agency for International Development to deliver surplus wheat and oil to Liberia.

"Rather than help their fellow citizens in need, these defendants sold food intended as aid and pocketed the proceeds," US Assistant Attorney General Lanny Breuer is quoted by the AFP news agency as saying.

The federal court jury in Washington also found that Fahnbulleh and Bondo had stolen construction materials and built themselves several homes.

"Fraud involving taxpayer funds, whether in the United States or abroad, will not go unpunished," Breuer said.

The scam began in 2005, as Liberia emerged from the conflict that claimed some 300,000 lives, displaced more than three million people and left the country's infrastructure and economy in tatters.

A third worker of the same charity was arrested in Liberia earlier this year and is fighting extradition to the US.