Hotels have been accused of trying to manipulate their ratings on the site by paying third parties.

Millions of holidaymakers are being misled by phoney reviews on leading travel website TripAdvisor, it has been claimed.

Hotels have been accused of trying to manipulate their ratings on the site by paying third parties to lavish fake praise and five-star write-ups on their establishments – and to rubbish their rivals.

Fakespot, a website that seeks to weed out bogus reviews, claims that up to a third of reviews posted on TripAdvisor are not legitimate. And its says that supposedly top-rated bed and breakfasts have almost twice as many ‘fake’ reviews as less favourably reviewed accommodation.

However TripAdvisor angrily rejected the claims as inaccurate, misleading and unreliable.

Fakespot founder Saoud Khalifa said: ‘I would advise TripAdvisor users to approach every review with scepticism.’

His company uses algorithms to seek the sort of language, posting patterns and account details that suggests a phoney review.

Another survey by the British Hospitality Association found that more than half of British hoteliers believe TripAdvisor is ‘not very helpful at all’ at dealing with malicious content. The website receives 50 million visits from the UK every month and it has been estimated that its reviews influence how £14 billion is spent annually.

While no company has been taken to court in the UK over fake reviews, the owner of a firm that sold fake TripAdvisor write-ups in Italy was jailed for nine months.

A TripAdvisor spokesman said: ‘We totally reject the inaccurate and misleading findings [of Fakespot]. The usefulness and accuracy of the content on TripAdvisor is what has made our site popular to hundreds of millions of consumers. It’s why we fight fake reviews so aggressively.

‘The claims about fake reviews are based on entirely flawed techniques. Their methods are unreliable for one simple reason: they have no access to the technical data you would need to determine whether or not a review is fake. We do – and we have been using this data for over a decade to track millions of reviews.

‘If Fakespot’s methods were in any way reliable, we would be using them. We have tested their analysis, with reviews we know to be either genuine or fake, and the results show it to be completely unreliable and inaccurate.’