A British car dealer could sell the world's most expensive car – if the right buyer is found for a unique £20m Aston Martin.

If it makes more than the asking price, it will easily become the most expensive car ever sold in Britain. And if interest peaks and the price goes up a further £2m – a drop in the ocean to these buyers – it will become the most expensive car ever sold in the world.

The car in question is a 1957 Aston Martin DBR1/2 and it is being offered for sale by Berkshire-based Ferrari specialist Talacrest.

It's the only car from the British sports car firm to have ever won the grueling Le Mans 24 hours endurance race. It took the chequered flag in the hands of motorsport aces Roy Salvadori and Carroll Shelby.

It's that pedigree which makes the car irresistible to racing car enthusiasts worldwide, and the car's sale takes on further poignancy as both Salvadori and Shelby died earlier this year.

"The Shelby connection will make this car of particular interest to American collectors," Talacrest's founder John Collins exclusively told Autoblog. "This is an extremely important car which deserves a good home."

Collins also told us he has already turned down "a couple of offers" which were "too far away" from the £20m asking price.

It's not just Le Mans the DBR1 is famous for, though. The Aston also took wins at Spa, the Nurburgring 1000km, Sebring, and also took first place in the 1959 Tourist Trophy at Goodwood with Sir Stirling Moss behind the wheel, crowing Aston Martin World Sports Car champions.

Collins added: "I found the car in France 20 years ago, and I sold the car to its last owner. It's been on display and has participated in racing events all around the world for the past two decades. This is a very important car."

View the car here on Talacrest's website