Around 25 licensees a week have been contacting the Federation Against Copyright Theft (FACT) with enquiries about firms that offer cheap subscriptions for televised Premiership football.
Hosts across the country are anxious to find a legal alternative to Sky, following the company's recent price hikes for the coming football season.
FACT says Sky is the only supplier with permission from the Football Association to show Premiership games in the UK so it is illegal for pubs to receive football from anyone other than Sky.
But a number of equipment suppliers are known to be offering pubs cut-price access to Premiership matches by using transmissions from abroad.
Last week the Morning Advertiser highlighted one firm, Dream Box, which offers a whole season of Premiership fixtures for less than £2,000.
FACT operations director Jim Angell said he would always warn licensees to steer clear of suppliers such as Dream Box. 'I can't offer any other advice. It's simply not legal.
Angell warned that a renewed crackdown would focus on both those that use domestic packages to show games in the bar area and those that show football via foreign satellites.
Meanwhile, some hosts have reported their Sky bills have risen by more than a third on top of the latest price rise because they are no longer able to suspend the service over the summer.
A Sky spokeswoman said that the terms of the contract had never changed. 'It has always been a 12-month contract, she said. 'Pubs have never been allowed to suspend the service, but it has happened in one or two places on an ad-hoc basis. The terms have not changed, we are just enforcing them more strictly now.
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