A gambling firm has admitted handing out free bets to customers in exchange for online reviews. Betway offered the incentive of a £5 wager if a customer leaves feedback for it on Britain’s biggest review site, Trustpilot, leading to a reported surge in five-star ratings. The bookmaker said the offer applied to both “positive and negative reviews” after it was accused by the deputy leader of the Labour Party of compromising the industry’s credibility. An analysis by The Times found Betway had gone from receiving eight five-star reviews on Trustpilot in June 2016 to 565 last month – with more than 6,000 top-rated reviews overall.Betting customers have been offered the incentive since 2017, the newspaper reported. Among the feedback which has helped lift Betway to a 4.3 rating out of 5 are several comments which make no sense, including one saying: “Good morning gofofofokfof”.Trustpilot claimed the offer was within their guidelines as customers were not being encouraged to leave only positive reviews. But Tom Watson, the Labour MP, told The Times: “The credibility of any industry depends on a culture of integrity and trust. “When it comes to the gambling industry, this has too often been in short supply. A spokesman for Betway said: “Like many companies we encourage customers to leave reviews and in accordance with Trustpilot’s guidelines we sometimes offer incentives. These incentives are offered for both positive and negative reviews.“We work closely with Trustpilot to challenge fake reviews or incorrect information, although it is Trustpilot’s responsibility to monitor and remove fake reviews; or those which don’t make sense.”A spokesman for Trustpilot said: “We have looked at how Betway runs its incentive and have no evidence to suggest that Betway is using incentives to request only positive reviews. Their invitation templates currently fall in line with our guidelines.” Want the best of The Telegraph direct to your email and WhatsApp? Sign up to our free twice-daily Front Page newsletter and new audio briefings. “Incentivising customers through sham bonuses is bad enough, but when coupled with encouraging false reviews, all credibility is lost.”There was also evidence that many of the reviews on Trustpilot had been written specifically to claim the bet, as Betway suggested customers posted their username with the feedback.More than 40 reviews reportedly had the word “username” included in them.