A "Nigerian letter" scam gang fleeced 34 victims out of €5 MILLION in cash.
Police in Spain arrested 31 members of the gang as they smashed apart the operation, which had been using emails, letters and social media to draw people in an steal the equivalent of £4.2m.
A spokesman for Policia Nacional said: "The use of previous information obtained from possible frauds allowed them to give a different treatment to each victim.
"[They] adapted the "story" they used to deceive them, which included prizes in the Spanish lottery of those who had turned out to be beneficiaries, profitable business or any other operation that supposedly would report to the injured millionaires profits."
"Once the victim was contacted by the members of the organisation in Spain, they began to ask him to make various payments in various concepts, such as customs fees, payment of attorneys' fees and notaries or taxes," the spokesman continued.
"When they had the victim hooked for having made several of these payments, they proposed to travel to Spain to see their money in person.
"In this way they reinforced the conviction of their participation in a profitable business, for which it was worthwhile to pay the important amounts in advance of which they were paying.
"The urgency with which they performed all the staging of the scams was no accident.
"They did so because the deceived, all foreigners, usually arrived tired off the flights and did not pay the same attention."
In addition to the US citizen, victims from Britain, Japan, Slovenia, Russia, Poland, Libya, Canada, Italy, Sweden, France, Switzerland, Saudi Arabia, Germany, Turkey, Brazil and China, have been identified.
Along with the cash more than 1,500 letters written and waiting to be sent to potential victims were found.