"While small in number, these reviews can significantly undermine the trust that consumers and the vast majority of sellers and manufacturers place in Amazon, which in turn tarnishes Amazon's brand," the technology giant said in its complaint, which was filed on Friday.



Amazon said it had conducted an investigation, which included purchasing fake customer reviews on Fiverr from people who promised five-star ratings and offered to allow purchasers to write reviews.



It said it had observed fake review sellers attempting to avoid detection by using multiple accounts from unique IP addresses.



Amazon said the lawsuit was not targeting Fiverr, which is not a defendant in the complaint. Fiverr said it was working with Amazon to resolve the issue.



"Amazon is bringing this action to protect its customers from this misconduct, by stopping defendants and uprooting the ecosystem in which they participate," the lawsuit says.



Anyone, whether they are a customer or not, has the ability to review products sold on Amazon's online store, but the rules of the site forbid paid-for or fictional reviews.