The BBC reports that eBay has been urged to tell users more about the risk of fraud by the consumer magazine, Computing Which. This called on the auction site to be more active in identifying its fraudulent users.
It also wants the site to warn users about the danger of fraud and to crack down on the selling of medical accessories such as contact lenses.
But the site's UK community manager said eBay already had a "safety centre" to help protect its users.
Computing Which? said the link to eBay's Safety Centre had to be made more visible. It said more than 130 incidents were reported to the Metropolitan Police each month.
The magazine said using the site's online money transfer system, Paypal, was safest because it did not involve divulging bank account details.
But eBay said the majority of the fraudulent cases did not take place on the site.
A statement said: "We have been led to believe that, in most of the cases, the users were contacted via e-mail - rather than on the eBay site.
"Payments were made using money transfer services such as Western Union, which are banned on eBay because they are not traceable."