The Competition and Markets Authority (CMA) is investigating online reviews, as it fears that consumers are being deceived by fake reviews and bogus paid-for endorsements.
The CMA estimates that more than half of UK adults (54%) use online reviews, and that 6% use blogs or vlogs before making purchases.
Nisha Arora, CMA senior director, consumer, said: “Millions of people look at online reviews and endorsements before making decisions such as where to stay on holiday, or which plumber to use.
“We have found that consumers who use online reviews and endorsements find them valuable, but we have also heard about some practices that may be unlawful.
“We have opened an investigation into businesses that may be paying for endorsements in blogs and other online articles where the payment may not have been made clear to readers.
“We have also published information for businesses to tell them what they need to do to help them stay within the law.”
Jackie Grech (pictured), legal and policy director for the British Hospitality Association, said: “Online user reviews have fundamentally changed the way people find, search and book restaurants and travel.
“They are powerful influencers for customers’ purchasing decisions, especially for hospitality purchases.
“Customers place increasing levels of trust in online user reviews, which makes them incredibly helpful when appropriately used but capable of really misleading consumers and harming business when misused or abused.
“We are pleased that the CMA has listened to the recommendations from our industry in their report and their recommendations going forward.”