The Pirate Bay co-founder Gottfrid Svartholm was flown from Cambodia, where he was detained last week, to Sweden on Tuesday to face charges unrelated to his pending one-year prison sentence for running the world's most notorious and illicit file-sharing service.

The 27-year-old, according to Swedish media – the Expressen – was arrested at the Arlanda Airport in Stockholm, suspected of hacking the Swedish tax authority and a contractor to it, Logica.

Two other Swedes have been arrested in relation to the Logica hack.

Sweden's Supreme Court in February upheld the prison sentences of the four men convicted of running The Pirate Bay. Peter Sunde faces eight months; Fredrik Neij, 10 months; Carl Lundström, four months; and Svartholm, one year. They share combined fines of more than $6.8 million. Lundström has served his time. Sunde is seeking clemency. Neij's whereabouts are unknown, and is believed to have fled Sweden.

They were convicted in 2009 in a joint civil and criminal proceeding in Sweden that pitted the entertainment industry and the government against the four defendants and the torrent-based file-sharing site, which points the way to free games, movies, software and music, much of it copyrighted. The service is used by millions and is notorious for its rebellious nature.

Juha Saarinen contributed to this report.