A 50-year-old American man, and his British partner, 38, were arrested in Algeciras, Cadiz, for allegedly fraud and credit card forgery.
The investigation began following a complaint from an international internet payment company which had been affected by an alleged fraud.
One of their users, whose full name they provided, had used credit cards copied and stolen in the US to obtain cash which he then sent to his own accounts.
The investigation, carried out in Estepona, Manilva, Guadiaro and Algeciras, led authorities to a couple living in the province.
They were located in Algeciras and their home was searched, resulting in four laptop computers, five external hard drives, six mobile phones, 19 credit cards and 4,500 GBP in cash being seized.
The detainee had accounts with payment management sites in the USA, the UK and Spain.
He had started the fraud with the accounts he used in the US to buy and sell products, which were linked to a US company owned by his partner.
He used the stolen and forged cards to supposedly purchase items from the company, sending the money, amounting to more than 348,372USD to his accounts in the UK and Spain.
Part of the money had then been transferred to an account in Manilva. The account, with €100,000, has been frozen by court order.