The founders of Scottish craft beer maker BrewDog claim that TV investors missed out on the chance to acquire a 20% stake in their business in 2009, prompting them to crowdfund the money that has since fuelled their rapid growth.

BrewDog’s own crowdfunding platform, Equity for Punks, has raised more than £56 million to date and is currently three-quarters of the way through its fifth funding round.

In 2016, the Scottish company announced that it would expand the scheme to the US, with plans for a 100,000-square-foot brewery in Ohio and a roster of new beers.

But almost a decade ago, the firm was rejected from the BBC’s Dragon’s Den – the UK version of Shark Tank in the US – where start-ups and inventors compete for the attention of high-profile business investors. BrewDog co-founder James Watt claims producers told them their business “wasn’t a good-enough investment proposition”, and they were denied the chance to present to the ‘dragons’ at the last minute.

Watt, along with fellow co-founder Martin Dickie, planned to offer the investors a 20% stake in BrewDog in return for a £100,000 investment. He claims that sort of stake in the business would be worth £360 million – a 3,500% return – given the size of the business today.

There will be questions over those figures: the £360 million sum is based on an overall valuation of £1.8 billion in line with BrewDog’s current Equity for Punks offer. But, in April last year, the Aberdeenshire-based business offloaded a 23% stake to private equity group TSG Consumer Partners for £213 million, representing a business valuation of £926 million – barely half of the £1.8 billion figure cited.

But there’s little doubt that a 20% holding in one of the world’s most successful and rapidly growing craft beer makers would have represented a sizeable investment for dragons including Peter Jones, Deborah Meaden or James Caan.

James Watt said: “Since the producers turned us down, we have gone on to build a pretty neat little business which is currently valued at £1.8 billion and which has raised over £250 million. Had we been able to pitch (and had any of the Dragons invested) that £100,000 would now be worth a whopping £360 million. It would have been by far the most lucrative investment not only in the history of Dragon’s Den but pretty much in investment history overall.

“Looking back, despite how much of a setback it was at the time, we are actually really happy we got turned down. It forced Martin and I to go back to the drawing board in terms of how to finance our business. As a result we created a model that lets the people who enjoy our beer own a part of our company. Equity for Punks would not have existed without the Dragons Den rejection.

“We now have a community of over 75,000 Equity Punk investors all over the world who are the heart and soul of our business. The Dragon’s loss was our amazing Equity Punks gain. It definitely worked out for the better, in our eyes.”