A federal court in Florida has sentenced Ghanaian-American Kelvin Owusu Nkwantabisa to 17 years' imprisonment for masterminding a US$38 million Business Email Compromise (BEC) fraud scheme that targeted businesses and individuals across the United States and around the world.

According to prosecutors, Nkwantabisa, 33, who operated under the aliases Kevin Brown and KO, led the United States arm of a transnational cybercrime network that stole more than US$38 million through sophisticated email fraud.

Court documents revealed that members of the network gained unauthorised access to victims' email accounts and secretly monitored communications relating to pending business transactions and payments. The fraudsters then impersonated trusted business partners and redirected funds into bank accounts under their control.

Investigators said the criminal network used multiple bank accounts and shell companies to conceal the origin of the stolen funds and evade detection by authorities.

Prosecutors told the court that Nkwantabisa coordinated overseas accomplices, directed the establishment of bank accounts across several states, monitored incoming fraudulent transfers and instructed co-conspirators on how to launder the proceeds of the crime.

His central role in the operation resulted in the longest sentence handed down in the case.

Three other members of the network were also sentenced.

Leshea Moore, 29, of Georgia, received more than 11 years in prison after admitting to creating shell companies, opening fraudulent bank accounts and helping to move stolen funds.

John Jouissance, 33, of Ohio, was sentenced to four years after pleading guilty to establishing shell companies and bank accounts used to receive illicit proceeds.

Justice Amoh, 37, of New York, who operated under the alias Samuel Andrews, received a three-year prison sentence for opening accounts using false identities and processing fraudulent transactions at Nkwantabisa's direction.

Commenting on the case, United States Attorney Jason A. Reding Quiñones said the defendants exploited legitimate business relationships and abused the trust of their victims to steal millions of dollars.

He noted that the convictions send a strong message to individuals who seek to use the American financial system to facilitate fraud and money laundering.

The investigation was led by Homeland Security Investigations (HSI) Fort Lauderdale, while prosecutors from the United States Attorney's Office for the Southern District of Florida handled the case.

Business Email Compromise schemes remain one of the most costly forms of cybercrime globally, causing billions of dollars in losses to businesses and individuals each year. The sentencing forms part of a broader effort by United States authorities to crack down on transnational l financial and cybercrime networks.