Consumer experts claim fake reviews are infiltrating platforms including Google, Facebook, and Trustpilot.
Which? says it was easily able to arrange for dodgy reviews to be published online.
The group's consumer law expert Lisa Webb says buying them was worryingly cheap:
"These fake reviews that are being sold by unscrupulous brokers. They can be acquired for as little as £4 so dodgy companies can go out there find these brokers and get reviews that will mislead consumers."
