A series of police raids in the UK has led to the arrest of five people as part of an ongoing crackdown on the sale of TV set-top boxes modified to stream paid-for services for free. A spokesperson for Federation Against Copyright Theft (Fact) claims that the latest series of arrests "should send out a clear warning to anyone involved in the sale and distribution of illegal set-top boxes".

The raids mark the latest move in an effort to stem the rise of 'Kodi boxes' – an unofficial name given to TV-compatible media-streaming devices preloaded with open-source Kodi software and third-party add-ons, many of which are dedicated to providing access to free streams of subscription movies, live sport and TV shows.

According to the BBC, the five arrests were made in Bolton, Bootle, Cheadle, Manchester and Rhyl, with the unnamed quintet reportedly having banked around £250,000 (€293,000) by selling the modified streaming devices online. The five are believed have been released on bail following questioning.

Director general of Fact, Kieron Sharp, explained to the BBC that its "day of action" was part of an ongoing battle to protect licensed content from TV subscription providers such as Sky, BT and Virgin Media, as well as sporting organisations such as Premier League football.

"Set-top boxes loaded with apps and add-ons allowing access to copyright-infringing material are very much illegal and anyone involved in selling these boxes should not be surprised to receive a knock on the door," said Sharp.

The legality of selling "fully loaded" devices with questionable Kodi add-ons will likely be decided once and for all in a court trial later this year. The landmark trial was set after a shop owner from Middlesbrough pleaded not guilty after being accused of facilitating the circumvention of copyright protection by selling modified 'Kodi boxes' in his local store.