A string of unnamed web companies are to be investigated into the non-disclosure of paid endorsements and for publishing bogus reviews of products.
Travel brands are expected to be included in the investigation, triggered after a consultation by the Competition & MArkets Authority in the UK which started earlier this year found instances of "potentially misleading practices".
The issues include:
- Fake reviews being posted onto review sites
- Negative reviews not being published
- Businesses paying for endorsements in blogs and other online articles without this being made clear to consumers.
In particular the CMA says it is assessing whether companies are breaking UK laws by not disclosing the paid-for endorsements.
The regulator estimates a total of £23.3 billion is spent annually of consumer products after reading an online review, with the majority (£14.4 billion) taken up by expenditure in travel and hotels sector.
The CMA's senior director for consumer affairs, Nisha Arora, says it wants to ensure consumer trust in "these important information tools is maintained".
TripAdvisor was not cited as one of the companies included in its probe, but the review giant has still issued a statement in support of the report and investigation.
An official says the recommendations put forward by the CMA "have been in place at TripAdvisor for years".

"As a leader in the online review space, we’re proud to be driving best practices in the sector and we welcome measures to eliminate bad practices in the wider online review industry, which will help to protect consumers and businesses alike.
"Nothing is more important to us than ensuring travelers gain an accurate and useful picture of the businesses and destinations they research on TripAdvisor.
"If people didn’t find our content useful and reliable, they wouldn’t keep coming back to our site."
The full report can be viewed and downloaded here.
NB:Review image via Shutterstock.