The 2021 promotion invited customers to find and claim a number of gold cans hidden in cases of the Scottish brewery’s beer.

Winners complained after discovering the cans were in fact only gold-plated and not solid gold as claimed in tweets about the promotion.

The Advertising Standards Authority (ASA) upheld the complaints, agreeing the three adverts were misleading.

James Watt, Brewdog’s CEO and founder, said it was a “costly mistake” and insisted that he “falsely thought” the cans were made from solid gold. He had “misunderstood the process of how they were made”.

Mr Watt said he contacted all 50 winners and offered them the “full cash amount”, and that “it ended up costing me around £470,000 — well over two-and-a-half years’ salary”, the BBC reports.