"They are going after small churches, claiming someone has left them a lot of money to improve their church or help others," U.S. postal inspector Steve Korinko told ABC News for an investigative report on the Nigerian scams to be aired Friday on 20/20 and World News with Charles Gibson.
The catch, says Korinko, is that the church has to pay a legal fee or a Nigerian tax to collect the money.
THE BLOTTER RECOMMENDS
An offer of $41,000,000 to the Hickory Ridge Community Church in Sussex County, Del., allowed scammers to cheat a group of prominent Christians out of $350,000.
"It was brilliant, absolutely brilliant," said Jeff Premo, an accountant hired by the church whose early skepticism about the offer ultimately dissolved after the Nigerians professed their faith.
"I thought I could ask them about, you know, 'Can you confess Jesus as Lord?' And they could answer all that," Premo told ABC News.
Premo traveled to Africa three times where he says the scammers posed as Nigerian diplomats. After he and the other community leaders ran out of money, Premo contacted the FBI and participated in an undercover sting that led to the arrest and conviction of the scammers in this country.
"They touched me on my hot button," Premo told ABC News about his faith. "Everybody had a hot button," he said.
U.S. postal inspectors say there are similar cases involving Christian churches being targeted across the country.
In Massachusetts, prosecutors say John Worley, an ordained minister and Christian psychotherapist, got so caught up in a Nigerian scam he went from being a victim to becoming an accomplice.
Convicted of fraud, Worley is currently serving a two-year prison sentence.
The widely-reported case of Mary Winkler, the Tennessee woman accused of murdering her minister husband, also grew out of a Nigerian scam, according to prosecutors.
Federal investigators say she had been cashing a series of counterfeit checks from Nigeria at a Tennessee bank.
Her family says she shot her husband after years of abuse.
In court, prosecutors have alleged she decided to shoot her husband after he confronted her about the scam.