Fourteen people from 13 companies have been arrested for illegally using cheap electricity to mine cryptocurrencies at industrial complexes in South Korea.

According to a report by the Yonhap news agency, the allegedly illegal mining activities were uncovered in four different complexes in the country’s southwestern city of Gwangju.

The report cites an announcement from the Gwangju Metropolitan Police Agency on Sunday regarding the accusation, which alleges violation of rules regarding factory use.

According to the report, companies setting up mining operations in such complexes are charged 10 percent lower electricity costs compared to companies in general areas, as well as lower rents.

The companies had each reportedly installed 100–350 mining devices in their facilities and had been mining cryptocurrencies since May 2017.

Six companies were located in the Hanam Industrial Complex, while the Nano and Pyeongdong Industrial Complexes each saw three cases and one was uncovered in Jingok Industrial Complex.

This isn’t the first time cryptocurrency miners have been accused of illegally using subsidized electricity in public or office areas in the country.

Last August, an electronics retail marketplace in South Korea reportedly took the unusual step of outlawing vendors from mining bitcoin in their stores.

Yongsam Market, an electronics shopping mall based in Seoul, banned mining citing increased utility bills and safety risks associated with the activity.

Bitcoin mining image via Shutterstock