Biodiesel producer Ecotec, on School Lane, gets waste produce from a major confectionery company and converts it into eco-friendly, cheap fuel.

And in the ultimate test, the chocolate invention is set to be used to power a car from the UK to Timbuktu, on the world's first carbon negative vehicle expedition.

Chris Elvey, one of the company's directors, said: "I put 100% bio-fuel in my car because it's quite heart-breaking having to go to the local petrol station and spend £1.05 a litre.

"It's in the experimental stage but conventional cars will run on it. But we're all dependant on the oil companies. Let's remove some of the dependency.

"There are roughly 8,000 small bars of chocolate in one tonne. This could equate to a car doing 50 miles to the gallon, going 3,300 miles."

To turn the chocolate into fuel, it is heated up and mixed with a number of chemicals.

The substance then splits to leave two liquids, one of which is cleaned and has a secret ingredient added, to become the biodiesel.

Manufacturers normally use vegetable oil to make eco-friendly fuel and 5% of vehicles in this country run on it.

The fuel, made from the oil in the chocolate, costs 15 pence a litre.

Chris said: "It's much better for the environment. We've got young children and we're doing it mainly for them – so there will be a biosphere for them to live on."