The billionaire founder of Foxtons estate agents is suing a top garage which serviced his £1m Lamborghini after the car blew up whilst his son was driving it.

Jon Hunt, says the wrong type of spark plugs were fitted to his Lamborghini Miura SV by the garage which serviced it last year.

The father of four, 61, whose wealth was put at £1.07bn by the Times Rich List this year, is suing H.R Owen Dealerships Ltd trading as Lamborghini London.

His son had driven less than a mile from the London garage after picking it up from the routine service when it exploded in flames.

Mr Hunt’s son was not hurt, but the rare 1971 supercar, which was the world’s fastest road car when it was first built, was reduced to a fire-blackened wreck on the A40 in Acton.

He is claiming £700k compensation, plus additional damages for storage and ‘loss of enjoyment’ of the vehicle, only 764 of which were ever built.

In a writ lodged at London’s High Court, Daniel Scarrott, for Mr Hunt, said: “H.R Owen owed Mr Hunt a duty of care to exercise the reasonable care and skill of an expert Lamborghini repairer and service.

“On December 19, 2012, Mr Hunt delivered the vehicle to the defendant’s garage on School Road, North Acton.

“The defendant carried out a service of the vehicle and replaced the engine oil, filter and spark plugs.”

On April 5, 2013, Mr Hunt collected the serviced car from the garage.”

Mr Scarrott added: “Mr Hunt’s son was then provided with the keys and proceeded to drive into London.

“As the vehicle proceeded along the A40, it did not appear to be running smoothly. Within less than one mile of the garage, the vehicle’s engine gave off a puff of white smoke.

“Mr Hunt’s son then proceeded to drive off with a view to returning to the garage. As he did so he noticed a smell of an old car, a further wisp of white smoke and an unexpected noise.

“There was then a deep percussion noise and the engine of the vehicle caught fire. In that fire the vehicle was substantially damaged.

“The spark plugs fitted worked at too high a temperature and created the risk of fire.

“The fire was caused by the ignition of fuel.”

Mr Scarrott also put forward an alternative case that the fire was caused by the engine’s timing being out and its carburettor not being properly adjusted.

Mr Hunt is claiming for the loss of the £900,000 car, but agrees to offset the £200,000 salvage value it has even as a burnt out shell.

H.R Owen’s defence was not available from the court and the contents of the writ have yet to be tested in evidence before a judge.