Internet firms face having to foot the cost of blocking sites being used to find and download pirated media after a landmark ruling was handed down in the High Court, ordering BT to close down the filesharing website NewzBin2 and pay the costs of making sure it cannot get back online.

Today's ruling, which formalises an earlier decision by Mr Justice Arnold that the Internet Service Provider (ISP) should be responsible for blocking its customers' access to the site, requires BT to block NewzBin2 at any IP address or URL it is using within 14 days and to continue to shut it down at others when asked to by the Motion Picture Association of America, which represents the Hollywood film studios and brought the case.

In court, it was also made clear that the action was being used as a test case and that similar rulings would be sought against the UK's other major ISPs.

Chris Marcich, President and Managing Director of the MPA in Europe, the Middle East and Africa, called the ruling a "win for the creative sector". He said: "Securing the intervention of the ISPs was the only way to put the commercial pirates out of reach for the majority of consumers. This move means that we can invest more in our own digital offerings delivering higher quality and more variety of products to the consumer."

But Mike O'Connor, Chief Executive of Consumer Focus said the ruling amounted to "playing whack-a-mole" with filesharing sites. He added: "Blocking websites like Newzbin 2 is a sticking plaster in terms of dealing with copyright infringement. We need a comprehensive strategy to address why people are paying for illegal services.

"The Competition Commission recently found that release windows for Hollywood movies on Sky limit consumers' choice in the pay-TV market. At the same time Netflix wants to launch an all-you-can-eat UK online movie subscription service, but is finding it difficult to get the necessary licensing in this country.

"The industry needs to focus their energies on coming up with an integrated strategy on how to move customers from illegal to legal services. Consumer demand for movies is huge. The challenge is for the industry to meet this demand by keeping up with technological advancements and providing affordable, legal choices for consumers, if it is to tackle copyright infringement in the long-term."

And Lee Myall, a director at online data firm Interoute, warned it could lead to ISPs being caught in a "game of cat and mouse". He said: "NewzBin2 will likely pop up across the internet, using different ISP addresses to mask its identity. While it is responsible to stop this piracy, placing the onus on BT to act as law enforcer, is effectively putting the handcuffs on the telecommunications industry."

Geoff Taylor, Chief Executive, BPI said: "It is high time that British musicians and creators had an effective way to deal with websites and services that rip off their music. This judgment is an important first step in that direction and shows responsible ISPs the way forward."

A BT spokesman said: "Today the Court determined the details of the blocking order specific to BT and the Newzbin website resulting from the Court?s judgment in July. It is helpful to have the order now and the clarity that it brings."