Pubs in Cardiff and Swansea suspected of showing Premier League football matches illegally using foreign satellites face prosecution, BBC Wales has learned.
In the last four months the Premier League’s private investigation firm has visited nearly 200 pubs in south Wales.
The League is planning to bring up to 100 prosecutions across Wales and England this season.
The first will be against The Rhyddings Hotel in Brynmill, Swansea, shortly.
Many south Wales pubs have subscriptions with foreign channels and show Cardiff City and Swansea City’s 15:00 GMT Saturday Premier League kick-offs.
These games are unavailable on the Premier League’s authorised UK broadcasters – Sky Sports and BT Sport – at the kick-off time.
By showing the foreign channels, the Premier League believes pubs are probably breaking copyright law.
In 2011 Karen Murphy, a Portsmouth pub landlady, won a court case against the Premier League.
The ruling effectively proved it is legal to buy a TV subscription from anywhere in the EU.
However, when a pub or club uses such a subscription to show Premier League football matches, it is breaking copyright law if the League’s logo is shown in on-screen graphics, or if the League’s anthem is heard before kick-off or at half time.
Tom Richards, a barrister specialising in copyright law, said it was unlikely a pub could screen the games without breaching Premier League copyright.
“The Premier League owns the copyright in its logo, in its anthem and in other bits of sound recording and artwork which are superimposed on any feed of a Premier League match,” he said.
“If you play those in a pub without the Premier League’s consent that’s copyright infringement in the law of copyright.
“Technically speaking, there is a loophole.
“If you could separate out the copyrighted content, such as the Premier League logo, from the match footage, then in theory you wouldn’t be infringing copyright.