The Advertising Standards Authority (ASA) has told TripAdvisor that it could not claim that all of its reviews were genuine and written by real travelers, following an analysis of its content.

After complaints from website users, the advertising watchdog questioned TripAdvisor over misleading statements claiming "Reviews you can trust", "Read reviews from real travellers" and "More than 50 million honest travel reviews and opinions from real travelers around the world".

The ASA said consumers could take the claims to mean they would be certain of the reviews. However it is believed that TripAdvisor did not verify reviews to the required standards and therefore could not prove they were from genuine travelers, News Limited reported.

TripAdvisor responded by saying they used a highly effective, advanced fraud detection systems and dedicated resources to minimise any non-genuine content, but it was not practical to screen each review manually.

Reviewers on the website are asked to sign a declaration stating their review is genuine and honest, however the ASA said this was not foolproof in preventing bogus reviews from being posted on the site.

The company also said that hotel owners were allowed to respond publicly to reviews and added that the website's users had experience in other review sites and therefore had "healthy scepticism".