Danny Krywyj, of Derby, appeared on the hit BBC show in 2005 with a camera kit designed to be strapped to the helmet of extreme sports enthusiasts.

His pitch was rejected by the Dragons due to a lack of patent protection.

But Balfour Beatty stepped-in and challenged Krywyj to redevelop the technology to allow it to be inserted into a water main.

The company set up by Danny – JD7 – is now one of the UK’s leading camera technology specialists and is forecast to turnover £3.2m this year.

The company is now entirely focused on pipeline assessment and inspection equipment for the utilities sector.

Krywyj said: “Before being approached by Balfour Beatty, JD7 had no experience of working in the utilities sector. By working in partnership, the technology has come on in leaps and bounds.

“In 2006 we carried out first successful inspection, using a camera to look at only one metre of pipe. Today we can carry out all sorts of surveys on lengths of water mains of up to one kilometre.”

Probes now carry equipment such as hydrophones, which ‘listen’ for the tell-tale noises caused by leaks, and ultrasound, which can scan the inside of a water main and give engineers a complete assessment of the condition of a pipe.

It allows them to predict when it will need replacing, allowing water companies to carry out proactive work to prevent expensive and disruptive bursts.

All of this work can be carried out without digging a hole in the road or switching off the water supply, giving huge efficiencies to water companies and reducing disruption for road users.

Colin Kelly, Managing Director of Balfour Beatty – UK Gas & Water said: “Our long relationship with JD7 has been mutually beneficial for both partners.

“It has allowed each of us to focus on what we do best; Balfour Beatty can deliver the latest innovations to better support our clients and the challenges they are facing, whilst JD7 is able to focus on research and development, knowing it has access to a wealth of industry knowledge and experience when it needs it.

“We believe that this kind of relationship between large Plcs and specialist SMEs is a sustainable way of working together.

“It also offers great benefits to the wider industry, as innovations find their way to the market quicker, giving utility companies access to the latest technologies.”