Kennedy Ikponmwosa was extradited from Spain and had a U.S. court appearance on April 18.

Others alleged to have helped run the scheme are Ezennia Peter Neboh, 48, and Prince Amos Okey Ezemma, 49, of Madrid, Spain; and Emmanuel Samuel, 39, of London.

The charges include conspiracy to commit mail and wire fraud, as well as mail fraud and wire fraud. Each count carries a maximum of 20 years in prison.

According to court documents the defendants are charged with operating an inheritance fraud scheme.

The Justice Department said that over a span of more than five years “they allegedly sent personalized letters to elderly consumers in the United States, falsely claiming that the sender was a representative of a bank in Spain and that the recipient was entitled to receive a multimillion-dollar inheritance left for the recipient by a family member who purportedly had died years before in Spain.”

The Justice Department said the victims were told that before they could retrieve the inheritance, they were required to send money for fees, taxes and payments to avoid questioning from government authorities.

The victims sent money to the defendants through a complex web of U.S.-based former victims who were persuaded to act as money mules for the alleged conspirators.

“The Department of Justice’s Consumer Protection Branch will pursue and prosecute transnational criminals who defraud U.S. consumers, wherever they are located,” Principal Deputy Assistant Attorney General Brian M. Boynton said in a statement. “And U.S. law enforcement will continue to work closely with law enforcement partners across the globe to bring to justice criminals who attempt to defraud U.S. victims from outside the United States.”