British music fans are being warned they could face legal action for downloading music from a leading website.
Thousands of British users have been using the Russian-based website AllofMP3.com to download tracks and albums at a fraction of their usual cost.
But the website, which poses as a legitimate online store, actually sells pirated recordings.
Now, the British music industry body, the BPI, said it will consider tracking down people who have breached copyright laws by downloading illegal tracks.
Around 14 per cent of all downloads in the UK are through the website.
A leading lawyer said that users of the site should wake up to the fact that they are funding criminals.
"Many users who download music from this site are likely to assume that as the site states it complies with Russian law and licence, and fees are being paid, everything is above board," said Alice Gould, a partner at law firm Wedlake bell.
"A huge number of people could be inadvertently breaking the law."
AllofMP3 claims that a loophole in Russian copyright law allows it to sell tracks considerably cheaper than its western rivals.
An entire album typically costs about ?1 to buy from the site, compared with 79p for an individual track through Apple's iTunes Music Store.
It is not known exactly how many British users of the website realise that they are breaking the law, but Ms Gould believes that users should realise their mistake before they are faced with the consequences.
The US media industry has already put pressure on Russian officials to close AllofMP3, to no avail.
Reports have even suggested that American companies are taking the matter so seriously that it could quash Russia's attempt to join the World Trade Organisation