It would not surprise me that a version of it may have found its way on to the web

Paramount Pictures

The news shows that soon the film industry could be facing a Napster-like erosion of its hold over anything it produces.

Already high-quality full-length versions of many blockbusters can be downloaded for free from the web soon after they go on release or appear on video.

The film industry is having to fight back with legal action and clever technology that it hopes will help stem the rising tide of piracy.

Lara copies

The film version of Tomb Raider, that stars Angelina Jolie as Lara Croft, is expected to be one of the bigger movies of the summer. But the impact of the movie could be dented because pre-release versions of the film are said to be already circulating on the net.

Angelina Jolie is playing Lara Croft in the Tomb Raider movie

Net veterans who trade movies online told BBC News Online they had heard the film was being traded on net chat channels, one of the many places that pirated movies and music can be found online.

"It would not surprise me that a version of it may have found its way on to the web," said a spokesman for Paramount Pictures, which will be distributing the film.

He said most films tended to be pirated when they were being prepared for release on video and several "beta" copies of the movie were in circulation.

Poor quality

The film industry has always had a problem with piracy. Poor-quality pirate copies shot with video cameras in cinemas have been available for years. But net technology is accelerating the speed at which illegal copies can be distributed, vastly increasing the potential audience for the illegal material and helping pirates produce ever better copies.

The computerised Ms Croft

Anyone who uses one of the peer-to-peer networks such as Gnutella and iMesh will know that high-quality versions of many movies are available to anyone with a fast net connection or the patience to download it via a slow modem.

These systems are hard to shut down because they have no central server that controls the network.

One of the reasons that pirated music is so popular on the net is because it takes relatively little time to download. One minute of music takes up roughly one megabyte of disk space.

'Saving grace'

By contrast, films are huge. The average digital copy of a film encoded with the most parsimonious video coding software is about 250 megabytes in size, and would take over 12 hours to download using the fastest modem.

Our saving grace is that it still takes so long to download pirated material

Federation Against Copyright Theft

A spokesman for the UK's Federation Against Copyright Theft (Fact) said the relative scarcity of broadband connections to the net was the only thing stopping piracy getting out of hand.

"On the internet, piracy is a function of the speed of downloading," he said. "Our saving grace is that it still takes so long to download pirated material."

A bigger problem at the moment is the use people are making of the net to order pirated copies of movies. "Our main problem is orders generating imports from Asia of pirate CDs and good-quality counterfeits from pressing plants," said the Fact spokesman.

New technology

But Europe, like the US, is making attempts to stop piracy. Lavinia Carey, director of the Alliance Against Counterfeiting and Piracy, said the EU copyright directive was soon expected to outlaw or place restrictions on the manufacture and sale of technology that could be used to crack encryption systems that protected DVDs and CDs.

The US version of this law has been the subject of fierce controversy, with many people claiming that the record and film industries are using the law to conceal shoddy technology and restrict intellectual freedom.

She said the film and music industries regularly issued cease-and-desist notices to websites and net service providers who were harbouring or exchanging pirated music or movies.

Earlier this year, the Motion Picture Association of America sent hundreds of letters to net service companies and universities telling them to clamp down on the trading of copyrighted material taking place through their networks.

Ms Carey said the end of the year would see trials of a system that would keep an eye on what was being done on the net with copyrighted content such as films and music CDs.