One in three Premier League football fans say they regularly watch matches live online via unofficial streams available on Kodi or other media players.
In a poll of 1,000 people for BBC Radio 5 Live , just over a third (36%) said they stream matches online through an unofficial provider at least once a month – and 22% do it at least once a week.
Younger fans are considerably more likely than their older counterparts to say they stream live football matches online through an unofficial provider. Almost two thirds of those aged 18-34 do so at least once a month, compared to just one third of 35-54 year olds and 13% of those aged 55+.
Of those fans who stream matches illegally, the most popular reasons are because a friend or family member does it and they just watch (29%); because the quality of online streaming is good (25%), and because sports TV packages are not good value for money (24%).
Just under a third of those surveyed said they do not know whether it is illegal to stream live Premier League matches online from unofficial providers, but another third believe it is always illegal.
The news comes after a ruling by the European Court of Justice in April put pirated streams on the same legal footing as copyright-infringing downloads, making it illegal to watch them.
"People need to be aware that this is no longer a grey area, in fact it is very black and white," said Kieron Sharp, director general of the UK Federation against Copyright Theft.
"If you are accessing content for free such as sport, TV and films for which you’d normally need a subscription, or go to the cinema, or buy a DVD, this is illegal."
Ealier this year, the Premier League secured a High Court order that allows it to shut down illegal video streams of football matches by blocking access to the computer servers on which they are hosted.
Previously, rights holders were only able to shut down individual streams, which could be re-established relatively easily, so fighting piracy was like a game of whack-a-mole.
"For the first time this will enable the Premier League to disrupt and prevent the illegal streaming of our matches via IPTV, so-called Kodi, boxes," A Premier League spokesman said.
Fans who want to continue to watch live football on TV are urged to subscribe to official channels such as Sky Sports or BT Sport, or watch games at a venue that charges for access.
Kodi is one of the most popular ways to watch pirated video content in the UK.
According to a recent survey commissioned by the security firm Irdeto, one in ten Brits who admit to watching pirated content say they use a Kodi box to do so .
Although Kodi boxes are not illegal, many of these Kodi devices come pre-loaded with third party plug-ins and add-ons that allow users to stream pirated content to their TV.
Interestingly, Irdeto’s research revealed that live sports was not the most popular type of pirated video content on Kodi – with movies and TV series topping of the list.
The only countries that indicated that live sports was the type of pirated video content they were most interested in were Portugal (25%), Egypt (23%) and the Gulf Cooperation Council (19%).
More men in each country indicated that live sports is the type of content they are most interested in pirating, while a majority of women prefer to pirate TV series.