A 28-year-old ex-pizza delivery boy has become one of Britain’s wealthiest young entrepreneurs after sealing a deal which values his business at over £1 billion.

Ben Francis founded fitness clothing brand Gymshark in 2011 as a 19-year-old student from his parent’s garage before rapidly expanding the company after gaining traction on social media.

On Friday, he confirmed that the company has sealed an investment deal which will value the Solihull-based company at more than £1 billion.

It has gained the mammoth valuation after US-based private equity firm General Atlantic sealed an investment in the company to take a 21% stake.

The deal will value Mr Francis’ stake, of around 70% of the company, at more than £700 million.

The retail business currently employs around 500 staff and raked in revenues of over £250 million in its last fiscal year.

He said: “It has been an incredible ride over the last eight years to get to this point, but today signals the next chapter in the Gymshark story.

“We are nothing without our community, so we will use this new investment partnership to get even closer to them on a truly global scale.

“I’m incredibly proud of what Gymshark has achieved to date from our roots in Birmingham, but it’s all about looking forward.

“I firmly believe Gymshark has the potential to be to the UK what Nike is to the US and Adidas is to Germany, and today is a significant step to realising that.”

Gabriel Caillaux, co-president, managing director and head of General Atlantic’s European business said: “We believe Gymshark is an authentic, disruptive and differentiated brand. Against a backdrop of rising social media usage, rapid growth of e-commerce and increasing focus on health and wellness, Gymshark is positioned to seize the opportunity of further growth.”