More than 100 people were arrested across Europe for stealing £10.6 million ($14.3m) from banks in the US.
The scam, which used shell companies in Europe, led to police freezing 87 bank accounts containing £1.1m.
More than 80 properties were searched and the 105 people arrested include a British citizen, two Austrians, 11 Greeks and 23 people in Spain.
Video footage of the raids shows €406,000 ($486,674) in cash and 14 luxury cars seized by police.
The eight-month operation by Europe's crime agency Europol and led by the Spanish National Police and the US Secret Service, resulted in the dismantling of an organised crime group involved in fraud and money laundering.
More than 50 American financial institutions were victims of the fraud, losing more than £10.6m.
"The criminal organisation, mainly formed of Greek nationals, set up shell companies in the United States and opened bank accounts for these companies," Europol said.
"To gain the trust of the financial institutions, members of the criminal network made transfers to the US-based accounts from different locations in the EU.
"Based on this trust, the American-based banks issued debit and credit cards for these accounts. Retailers in on the scam, most of whom were in Spain, used the payment cards to finance the available credited amounts on the cards.
"To launder the stolen funds, they transferred them to different bank accounts, owned by members of the criminal network located in several EU countries."
The Joint Cybercrime Action Taskforce at Europol supported the operation using a team of cyber liaison officers. The operation involved police services from Austria, Denmark and Greece, as well as the US Department of Justice and the US Financial Crimes Enforcement Network.