Earlier this month, it was announced some of the filming for series five of the fantasy drama, starring Lena Headey, would take place in and around the Spanish city of Seville.
Within 24 hours, more than 10,000 citizens had applied to work as extras on the show.
Two men set up a fake website claiming to be the official Spanish casting company's site, and hopefuls were instructed to call a premium-rate telephone number to make their application.
Callers were kept on the phone for at least six minutes, at a cost of £8, before being given the real casting address. The men managed to rake in £79,000 a week, according to Spanish police.
A spokesperson said: "The fraudsters, who are based in Ibiza, created a website almost identical to the genuine Game of Thrones site.
"Given the success of the series and the excitement over the forthcoming filming of some episodes in Seville, the number of calls received was very high. It was the perfect hook for a big scam."
Game of Thrones is also partly filmed in Northern Ireland.