The US Federal Bureau of Investigation (FBI) has arrested 80 Nigerians for online fraud involving R606 million ($40 million).

The FBI says it is still hunting for a further 57 suspects, scattered across the globe, including in Africa.

According to the US authorities, the accused used various online fraud schemes – including business e-mail compromise (BEC) fraud, romance scams and schemes targeting the elderly – to defraud victims out of millions of dollars.

In a press conference yesterday, Nick Hanna, US attorney for the central district of California, said the fraud cases involved suspects colluding with federal and state agents to dupe unsuspecting victims.

"FBI agents, along with federal and state law enforcement authorities, arrested a total of 14 defendants in the US, all named in a sweeping fraud and money laundering case."

A statement issued yesterday by the US Attorney's Office says 252 counts had been opened against the 80 defendants, most of whom are Nigerian nationals, for participating in a massive conspiracy to steal millions of dollars through a variety of fraud schemes and launder the funds through a Los Angeles-based money laundering network.

"The indictment was unsealed after law enforcement authorities this morning [Thursday] arrested 14 defendants across the United States, with 11 of those arrests taking place in the Los Angeles region. Two defendants were already in federal custody on other charges, and one was arrested earlier this week. The remaining defendants are believed to be abroad, with most of them located in Nigeria."

According to the statement, the fraudsters targeted victims in the US and across the globe, including individuals, small and large businesses, and law firms. Some of the victims of the conspiracy lost hundreds of thousands of dollars to fraud schemes, and many were elderly.

"This case is part of our ongoing efforts to protect Americans from fraudulent online schemes and to bring to justice those who prey upon American citizens and businesses," said Hanna. "Today, we have taken a major step to disrupt criminal networks that use BEC schemes, romance scams and other frauds to fleece victims. This indictment sends a message that we will identify perpetrators – no matter where they reside – and we will cut off the flow of ill-gotten gains."

Three years ago, a South African woman and six Nigerian men, operating from SA, admitted to being part of a global fraud network that used online dating sites to reach potential victims.

Investigators learned the conspiracy involved more than 200 people worldwide, led out of SA and Nigeria, according to court papers. They got warrants for 360 e-mail accounts, obtaining about a million messages.