British shoppers are being warned to watch out for bogus customer reviews when buying online this Christmas.

The warning follows a survey of 2,000 adult online shoppers by customer review service Reevoo which found that peer reviews are five times more likely to influence online shoppers than adverts.

Britons are expected to spend a record £42bn online this festive season, and six out of 10 respondents said that opinions written by online consumers who have already bought a product would affect their choice of what to buy.

In contrast, just 12 per cent of respondents indicated that they would be swayed by online advertising.

"The influence of reviews is no longer in doubt and we think it is time that regulators looked at the way that customer reviews are presented online," said Richard Anson, chief executive of Reevoo.

"Given the influence of customer reviews it is time for regulation and standards to be applied so that customers are not misled."

However, the study also revealed that online shoppers are beginning to wake up to the possibility of fake reviews and will not believe everything they read online.

While 79 per cent admitted to being influenced by impartial ratings from shoppers who have definitely bought a product, only 14 per cent trusted review programmes directly managed by retailers.

And 36 per cent of consumers said that they were worried about the authenticity of retailer-managed customer review programmes.

Furthermore, eight out of 10 respondents agreed that there should be a regulatory requirement for published reviews to be written by customers who have genuinely bought a product.

Another 84 per cent believe that genuine customer reviews should carry an indicator making it clear that they are from a real purchaser and fully independent of the retailer.

"Opinion increasingly matters in the online world," said Anson. "Savvy shoppers are sharing opinions and exerting huge influence. While this is a great thing, it is important that opinions can be trusted."

Shoppers aged 35 to 44 were the most likely to be influenced by online reviews at 64 per cent of respondents, followed by the over 55s and 18 to 24 year-olds at 58 per cent of respondents.

Despite some controversy over price comparison websites not revealing certain commercial relationships with product providers, 71 per cent of online shoppers said that these sites still influenced their product choices.