The £2m Project One hypercar being built by Mercedes-AMG will be powered by four electric motors, a new report claims, adding just over 400 horsepower to the car's Formula One-sourced petrol engine and taking the total output to 1,020 horsepower.

The road-legal hypercar, which will be revealed in public for the first time at the Frankfurt motor show in September, was recently shown off in secret to a handful of well-heeled customers ready to pay up for the car, even before driving it.

A report by Automobile Magazine claims the Project One, which is yet to be given its real name, will have four electric motors producing 408hp and working in conjunction with a turbocharged engine taken from the Mercedes-AMG team's 2016 Formula One car.

It is claimed Mercedes is fitting two electric motors to the front axle, one to the crankshaft and another to the turbocharger. The two at the front will likely each power one wheel, enabling the car to accelerate or brake each front corner while turning to improve handling; the Honda NSX employs a similar system with its three electric motors.

As well as helping to give the car more power under acceleration – and recover energy back into the battery pack when braking – the motors will also be used to make the Project One emissions-free for up to 30 miles of gentle driving.

Mercedes-AMG is pitching the Project One as the ultimate road-going hypercar with the F1-sourced engine as its centrepiece. The company is adamant that this is not an engine "inspired by F1 technology" or with the same power as an F1 engine; it has now said numerous times that this road-legal car will be driven by an actual F1 engine.

For more on the Mercedes-AMG Project One, visit our complete guide, which will receive regular updates as more about the car is revealed.

Specifically, it will be the same 1.6-litre turbocharged V6 engine used by the company's 2016 Formula One car, which won both the Constructors' and Drivers' World Championships at the hands of Nico Rosberg and Lewis Hamilton. It will have the same 11,000rpm rev limiter and the same electric hybrid system.

The car will cost in the region of £2m (plus local taxes) and just 275 examples will be made; the first deliveries will begin in 2019.