A device that prevents drivers accidentally filling a diesel car with petrol has won a record £250,000 investment from the BBC2 show Dragons’ Den.

The misfuelling prevention device secured offers from three of the Dragons. James Caan offered the full £250,000, while Deborah Meaden and Theo Paphitis offered £125,000 each.

Company director Michael Cotton elected to sell a 25% company share to the pairing of Meaden and Paphitis. Meaden originally offered the full £250,000 for a 35% stake but then reduced her requirements.

“The investment means we can change from soft tool to hard tool production,” said Cotton. “This will reduce the price of the unit and quadruple volume to 20,000 a month.

“This is very much the beginning of the process. This advertising and exposure will bring a lot more people on board,” continued Cotton.

“We have interest from a lot of fleets such as Lloyds TSB and Arval and all three of the emergency services. We are also currently going through the process to receive Thatcham accreditation.”

It is claimed it can cost between £250 and £12,000 to fix a diesel car that has been filled with petrol.

The device can be fitted to most diesel vehicles and prevents the wider petrol pump nozzle fitting in to the tank. It currently retails at £69.99.

BMW, Land Rover and Ford currently fit their own misfuelling devices to new vehicles in their ranges.