The latest research into internet file sharing has shown that, far from decreasing, the amount of online piracy has risen sharply.

Data collected by Solutions Research Group shows that the number of people using P2P file sharing systems doubled from 2005 and 2006.

Nearly one in five US citizens had pirated films on their computers, and over two thirds of those downloaded a film at least once a month.

"There is a Robin Hood effect. Most people perceive celebrities and studios to be rich already and as a result don't think of movie downloading as a big deal," said study director Kaan Yigit.

"The current crop of 'download to own' movie services, and the new ones coming into the market, will need to offer greater flexibility of use, selection and low prices to convert current users to their services, otherwise file-sharing will continue to thrive."

The survey found that 80 per cent of movie downloaders only used P2P file-sharing sites rather than legitimate download services.

Only 40 per cent believe the downloading copyrighted movies from the internet is a 'very serious offence', compared to 58 per cent who believe that 'parking in a fire lane' is a 'very serious offence'.

The move will be a blow to industry bodies like the Recording Industry Association of America which believe that taking file sharers to court has reduced the amount of downloading.

The Solutions Research Group survey polled 2,600 US citizens and was carried out between June and September 2006.