Auction web sites are increasingly becoming a significant channel for the sale of counterfeit and illegal products, according to research.

For every £100 spent in web auctions, around £5 is spent on counterfeit items, says the study, which also revealed that the estimated value of fake goods including fashion and cosmetic items, consumer electronics, motor equipment and sports items sold over the web in the UK each year totals £800m.

Online auction sites such as eBay – found guilty by a French court this week for failing to prevent the sale of fake luxury goods on the internet – have become a second home for ‘grey market’ trading, in particular the sale of imported manufactured goods at highly inflated prices, says the report.

"Counterfeit goods dilute the value of brands, undermine the integrity of auction sites and ultimately cost the UK economy millions of pounds in lost income. But this is not just about protecting brand owners – it is also for the consumer’s benefit,” said joint global head of DLA Piper’s technology Simon Levine.

“Equally, this is not just a problem for the auction sites to address alone. Consumers need to report illegal or counterfeit trading and copyright owners need to work together with their legal representatives to take more active steps to police their brands online,” he said.

The study was carried out by law firm DLA Piper and online intellectual property infringement specialists ComSec International.