U.K. trade body the BPI has distanced itself from the methods employed by a law firm in chasing file-sharers.

The BBC reports that ACS:Law has sent thousands of letters to people it claims have infringed copyright over the Internet. Those accused are offered the chance to settle out of court for a fee; some have reportedly paid up, with fees averaging hundreds of pounds in each case.

But there is a suggestion from a lawyer acting on behalf of 100 people who received letters that no case has gone to court, and the evidence based on tracking an IP address is not strong enough to reach that legal stage.

ACS:Law told the BBC that cases are pending. It represents clients including German firm DigiProtect, which pursues file-sharers on behalf of rights holders.

Consumer body Which? has received approaches from 150 people who say they have received letters and are innocent of any illegal file-sharing. The Information Commissioner has been asked to investigate the ACS:Law letters by a law firm representing people who have received such letters.

The BPI said it only supports legal action as a last resort against persistent file-sharers. It backs the U.K. government's proposed Digital Economy Bill, although would prefer the graduated response system to be introduced at the start rather than depending on whether educational warning letters have the desired impact.