Young people aged between 11 and 24 are driving a new wave in digital piracy, and 14-year olds are the most likely to be file sharers, according to research by Microsoft.

The Real Thing study found that 54 per cent of children use file-sharing sites, compared with only 15 per cent of adults, and one in five children have bought illegal goods online, or through open auction web sites.

Younger generations are increasing inclined to choose free versions of " digital property" if possible, said the study. More than 60 per cent of children say they favour pirated goods, because legal versions are too expensive and more than 20 per cent see no difference between fakes and the real thing.

Parents should ensure they are aware of what their children are doing online, said Michala Wardell, head of anti-piracy at Microsoft in the UK.

"File sharing is a great technology, but parents should make sure that their children are doing it legally," she said.

"I would encourage parents to be aware of what their kids are doing without clamping down on their computer use, after all children are developing valuable technical skills by being online.

"But I would also stress that without fully understanding the risks of running illegal computer programs, kids could lose more than just their homework."