The United States government has placed sanctions on six Nigerians for alleged Internet-related fraud that caused American citizens and businesses over $6 million losses.

This was disclosed in a statement signed by the U.S. treasury secretary, Steven Mnuchin, and posted on the Treasury Department website on Tuesday.

"Today, in a coordinated action with the U.S. Department of Justice, the Department of the Treasury's Office of Foreign Assets Control (OFAC) took action against six Nigerian nationals for conducting an elaborate scheme to steal over six million dollars from victims across the United States," read the statement.

"The individuals designated today targeted U.S. businesses and individuals through deceptive global threats known as business email compromise (BEC) and romance fraud. American citizens lost over $6,000,000 due to these individuals' BEC fraud schemes, in which they impersonated business executives and requested and received wire transfers from legitimate business accounts.

"Money was also stolen from innocent Americans by romance fraud, in which the designees masqueraded as affectionate partners to gain trust from victims," the official added.

The individuals sanctioned are Richard Uzor - BEC scam - a loss in excess of $6,300,000 was attributed to the scam led by him and an accomplice; Michael Olorunyomi - Romance Fraud - losses exceeding $1 million was attributed to him.

Alex Ogunshakin, an accomplice to Mr Uzor, was allegedly contacting victims; Felix Okpoh - Romance Fraud - allegedly provided financial materials and technological tools to Mr Uzor.

Nnamdi Benson - Romance Fraud and money laundering; and Abiola Kayode - BEC and Romance Fraud - allegedly provided bank accounts to individuals involved in the scheme.

"Cybercriminals prey on vulnerable Americans and small businesses to deceive and defraud them," said the secretary Mr Mnuchin. "As technological advancement increasingly offers malicious actors tools that can be used for online attacks and schemes, the United States will continue to protect and defend at-risk Americans and businesses."

The secretary included the terms of the sanctions placed on the six Nigerians in his statement.

"Today's action includes the designation of six individuals pursuant to Executive Order (E.O.) 13694, as amended by E.O. 13757, which targets malicious cyber-enabled activities, including those related to the significant misappropriation of funds or economic resources for private financial gain.

"As a result of today's action, all property and interests in property of the designated persons that are in the possession or control of U.S. persons or within or transiting the United States are blocked, and U.S. persons generally are prohibited from dealing with them," read the statement.

The statement did not indicate the bases of the six persons, nor any information about their arrest.

The alleged fraudulent acts were committed between 2015 and 2017, according to the statement.