Teenagers and students have an average of more than 800 illegally copied songs each on their digital music players, the largest academic survey of young people's music ownership has found.

The research also showed that half of 14 to 24-year-olds were happy to share all the music on their hard drive, enabling others to copy hundreds, or thousands, of songs at any one time.

Although illegal copying has become widespread, the scale of the problem uncovered by the University of Hertfordshire left the music industry surprised. On average every iPod or digital music player contained 842 illegally copied songs.

Fergal Sharkey, former lead singer of the Undertones and now chief executive of British Music Rights, said: “I was one of those people who went around the back of the bike shed with songs I had taped off the radio the night before. But this totally dwarfs that, and anything we expected.”

The average digital music player carries 1,770 songs, meaning that 48 per cent of the collection is copied illegally. The proportion of illegally downloaded tracks rises to 61 per cent among 14 to 17-year-olds. In addition, 14 per cent of CDs (one in seven) in a young person's collection are copied.

Illegal copying in some form is undertaken by 96 per cent of 18 to 24-year-olds surveyed, falling to 89 per cent of those aged 14-17. Nearly two thirds copy CDs from friends, and similar proportions share songs by e-mail and copy all the music held on another person's hard drive, acquiring up to 10,000 songs in one go.

British Music Rights argues that the solution partly lies in developing new legal services that make breaking copyright unappealing.

Mr Sharkey said: “The positive message is that 80 per cent of downloaders said they would pay for a legal subscription-based service, and they told us they would be willing to pay more than a few pounds a month.”

British Music Rights declined to release the exact amount but it is believed to be about £10 a month.

The organisation is trying to help the record companies to persuade internet service providers to sign up to a new type of music service, in which vast catalogues of songs are available for an add-on fee to a broadband package. Agreements with providers such as Virgin Media are expected in the next few weeks.

In France last week, Orange, France Telecom's mobile arm, reached agreement with all four main record companies to provide downloads of more than a million songs to mobile phones and home computers for €12 (£9.40) a month.

Music sales have been falling steadily and the big companies are desperate to strike subscription-based agreements rather than rely on one-off CD and download sales.

Explore Personal Tech

• InGear