An international operation to crack down on a syndicate of “419 scammers”, dubbed the Yahoo Boys, was concluded this week when US Homeland Security came to South Africa and arrested 10 alleged fraudsters in Pretoria.

The operation has been under way since 2011, when US authorities discovered scammers with ties to a South African syndicate were operating brazenly on their soil.

Ten people were arrested during the operation, nine of whom were Nigerian men, and one a South African woman.

Hawks spokesman, Paul Ramaloko, said last night the Special Investigating Unit had helped with the arrests after US Homeland Security obtained an arrest warrant this month.

The 10 alleged scammers form part of a larger group of 17 who have been named as members of a syndicate, the Yahoo Boys.

According to charges filed by the US attorney’s office in Gulfport, Mississippi, against Oluyitan Olagoke of Brooklyn, New York – allegedly a member of the west African syndicate – the group are being charged with buying bank account information from hackers, stealing money and then sending cash or goods to South Africa and Nigeria.

They would, for example, enlist unsuspecting people through work-at-home scams or fake online romances to obtain their banking details which they would use to send stolen money or fraudulently purchased goods to South Africa and Nigeria.

In the charges, authorities alleged the proceeds were laundered “through a reshipping network of complicit and unwitting individuals recruited through internet scams”.

More than $60 000 (about R618 000) was taken from one brokerage account, the charges against Olagoke claimed. Court papers did not give a total amount taken by the ring.

Officials said investigators with US Immigration and Customs Enforcement had been probing the schemes since 2011. The charges cited seven Mississippi residents who had been victims.

The other alleged members of the syndicate were arrested in Canada, California, Wisconsin and Indiana.

Ramaloko said the 10 arrested here had appeared in the Pretoria Magistrate’s Court on Wednesday as part of their extradition. They would be tried alongside Olagoke in Gulfport. The case was postponed to Wednesday.

Craig Rosewarne, of Wolfpack Risk Assessment, a local online security company, said there were syndicates operating across the world.

South Africa was an especially soft target because of the lack of policing units focused on combating cybercrime.

Typically, ring members would communicate via online chatrooms and be divided into “breachers”, who specialised in gaining access to account information either through scam e-mails, phishing or hacking, the “wholesalers” who would buy up those details and sell them off, and the “runners”, who would use the information to draw money and buy goods.