Hollywood is hoping a law will be passed that would allow it to use hacking techniques to prevent the illegal download of music and movies from the internet.

A bill introduced in the US seeks to allow the industry to hack into personal computers to search for illegal material.

It could also allow technology to be used to disrupt or disable computers known to be trading in copyrighted films or music.

The biggest change would be the lifting of civil and criminal penalties against companies for "disabling, interfering with, blocking, diverting or otherwise impairing" pirated songs and movies.

Hollywood has long been keen on stopping illegal downloads

Users would get no warning of the "hacking" and would only have cause to sue if the violation caused more than $250 (�158) of damage.

Experts estimate the worldwide cost to the movie and music industries of internet piracy is $4.3bn (�2.9bn).

The proposed new legal powers could mean record companies avoiding the usual route of lengthy legal action against file-swapping services.

The bill was introduced by representative Howard Berman, the top democrat on the House Judiciary subcommittee on courts, the internet and intellectual property, and considered a friend of Hollywood.

Mr Berman said his bill "allowed copyright owners to use technology to deal with technological piracy".

He said the proposal would not give access to personal data kept on PCs or allow files to be destroyed or viruses to be spread.

'Theft'

Mr Berman said the technology would only allow them to disable illegally downloaded films or music.

He compared it to a car dealer repossessing a car which had not been paid for.

"There is no excuse or justification for this piracy," he said.

'Innovative'

"Theft is theft, whether it is shoplifting a CD in a record store, or illegally downloading a song."

But the move is not welcomed by everyone.

Alan Davidson, of the Center for Democracy and Technology, said the legislation provided "a hunting licence for copyright holders to seek out legitimate users of the internet".

The music industry led the way in trying to curb the activities of file-swapping services such as Napster, which has spent nearly a year battling lawsuits.

Recording Industry Association of America chief Hilary Rosen called the bill an "innovative approach to combating the serious problem of internet piracy".

The Motion Picture Association of America praised Berman's efforts but said in a statement: "There are aspects of the bill we believe need changing."