Lisa Webb, Which? consumer law expert, said that as advent calendars had become more luxurious, there were likely to be more criminals targeting consumers buying them.

“Since these products can be expensive, many people will be looking for discounted and cheaper options, but it’s important to be wary of scammers trying to take advantage in the run-up to Black Friday and Christmas,” she said.

Black Friday is a holiday sale that traditionally takes place the day after Thanksgiving in the US.

However, over time it has extended across the week, and now retailers often run Black Friday sales across the whole of November.

Last year, scam adverts claimed to offer the £350 advent calendar from perfume and beauty brand Jo Malone for just £30, external.

Ms Webb advised customers to check the URL of any website carefully and to question why something may be at such a low price. “If the deal seems too good to be true, often it is.”

She added that any suspicious sites can be reported directly to the National Cyber Security Centre, external.