Websites that help users download illegal films and music could be banned after a landmark ruling in Europe against one of the largest remaining file-sharing sites.

The European Court of Justice has ruled that The Pirate Bay, a notorious free downloads site, could be held liable for directing users to material that breaches copyright in a decision that has major implications for streaming services.

It said The Pirate Bay's owners "cannot be unaware" of the illegal material posted to its site and that it links to such content "with the purpose of obtaining a profit".

"Making available and managing an online platform for sharing copyright-protected works, such as 'The Pirate Bay', may constitute an infringement of copyright," said the court.

Websites including The Pirate Bay are already banned under UK law, with internet providers forced to block access to the website. Wednesday's ruling, which comes after Dutch campaigners asked the EU's highest court to make a decision on its legality, sets a precedent for other countries in Europe.

The Pirate Bay has been a bane to law enforcement since its launch in 2003, with raids on its offices and the arrest of its founders. It has survived while high profile competitors have shuttered.