One third of US and UK consumers are making illegal copies of DVDs, according to a recent study.

The survey of 5,331 citizens conducted by analyst firm Futuresource Consulting found that 38 per cent of UK users and 32 per cent of US users had copied a DVD disc within the past six months.

The number is up from 2007, when just a quarter of those surveyed admitted to copying a DVD.

Of those who had copied discs, 63 per cent in the UK and 77 per cent in the US said that they would otherwise have purchased the copied material.

"As studio revenues from DVD are in decline, protecting revenues is even more vital than 12 months ago," said the report.

"The vast majority of these copiers admit that they would purchase at least some of the titles on DVD if they had not been able to copy them, clearly indicating the significant levels of lost revenue due to home copying."

The study also found that 18-24 year-old males were the most likely to copy DVD material, while DVD players and recorders, along with PC software, were the preferred methods for copying.

Movies were the most commonly copied media, followed closely by TV shows and so-called 'special interest' DVD titles.

Copying of TV show DVDs saw the greatest increase. Some 61 per cent of users had copied a show this year, compared to just 42 per cent in 2007.