Amazon is investigating the most prolific reviewers on its UK website after a Financial Times investigation found evidence that they were profiting from posting thousands of five-star ratings.

Justin Fryer, the number one-ranked reviewer on Amazon.co.uk, reviewed £15,000 worth of products in August alone, from smartphones to electric scooters to gym equipment, giving his five-star approval on average once every four hours.

Overwhelmingly, those products were from little-known Chinese brands, who often offer to send reviewers products for free in return for positive posts. Mr. Fryer then appears to have sold many of the goods on eBay, making nearly £20,000 since June.