Self-billed as the largest travel community in the world, with more than 60 million reviews on hotels, restaurants and airlines around the world, travel industry insiders claim TripAdvisor is open to abuse from establishments intent on bringing their rivals into disrepute.

The claims have been validated by the Advertising Standards Authority, which admits some reviews may be ‘non-genuine’.

TripAdvisor has come into question after two hotels and a company called KwikChex, which specialises in online reputation management, challenged a claim on TripAdvisor that it “offers trusted advice from real travellers” and featured “honest travel reviews and opinions”.

They argued TripAdvisor’s claims were misleading as it had no way to vet all the reviews.

They even suggested more and more people were using reviews sites to extort discounts and money from businesses.

A KwikChex spokesman said: “It is small businesses that suffer most, as they tend to have few reviews and so the impact is much greater.”

The Advertising Standards Authority agreed TripAdvisor did suggest “the reviews posted were from genuine travellers, and accurately reflected those travellers’ experiences of the places they visited.”

The organisation said: “We understood that reviews could be placed on the site without any form of verification, and that whilst TripAdvisor took steps to monitor and deal with suspicious activity, it was possible that non-genuine content would appear on the site undetected.”

It added: “We did not consider that consumers would necessarily be able to detect and separate non-genuine reviews from genuine content, particularly where a hotel or other establishment had not received many reviews, and nor did we consider that a hotelier’s response in itself would go far enough to alert consumers to, and moderate, non-genuine content.”

The Advertising Standards Authority warned TripAdvisor never to appear in its previous form again.

A TripAdvisor spokesman said: “The ASA has taken a highly technical view around some marketing copy that was used in a limited capacity. We have confidence that the 50 million users who come to our site every month trust the reviews they read on TripAdvisor, which is why they keep coming back to us in increasingly larger numbers to plan and have the perfect trip.

“The average traveller reads dozens of reviews before making an informed decision, not just one or two. We know that our users approach TripAdvisor with common sense, and make an educated decision based on the opinions of many. If people did not feel the insight they gained from our site was an accurate reflection of their experience they wouldn’t keep coming back.”