Amazon is using artificial intelligence to combat fake product reviews and inflated star ratings, The Guardian reports.

It is employing a new AI machine-learning system that the online retailer built in-house to boost the prominence and weight of verified customer purchase reviews, those marked as helpful by other users and newer, more up-to-date critiques on its site.

The system will bring what Amazon thinks are more accurate reviews to the top and use them to create a star rating.

Previously star ratings were simply an average of all reviews, which allowed fake reviews to heavily influence the first-glance rating even if verified purchasers had slated the product.

The algorithm will improve over time, Amazon told technology site Cnet. Its first effects may not be visible for some time as the work only began on Friday.

Customer reviews have become the cornerstone of trust in the online shopping world. Where users cannot see in person what the products are like before they buy them, the ratings and reviews of users who have supposedly bought them before can make or break a product.