Another batch of expatriate South Koreans has been caught running an online sports betting site targeting their countrymen back home.

Over the weekend, police in Thailand arrested seven South Korean men accused of running an illegal online sports betting operation out of two adjoining condominiums in a Bangkok luxury tower. One condo housed the computer gear, while the men slept in the other.

Police said the ring had been operating for around three years, frequently shifting their location in a bid to avoid detection. Police reportedly received a tip-off from someone in the building who noticed that the condo in question was full of foreigners who didn’t seem to go out all that much.

Thai media reports said the ring generated between Bt30m and Bt90m (US $900k to $2.7m) per month from bettors in South Korea, although it’s unclear whether this sum was betting handle or profits. The seven arrested individuals have been charged with unlawful online gambling, illegal entry into the country and working without proper permits.