The new model, rumoured to be called i9, would use the same carbonfibre tub as the i8 but would get more aggressive styling, a larger engine and a more powerful electric motor.
The engine is understood to be the new modular 3.0-litre six-cylinder unit that is in development and set to appear first in the upcoming 7-series replacement.
The i9 will be the next model to join BMW’s i sub-brand. Also planned is the i5, a stretched version of the i3.
Currently in use in the i8 is a three-cylinder 1.5-litre turbocharged petrol engine in combination with an electric motor. Total power output is rated at 357bhp, alongside 420lb ft.
Expect the i9 to improve on the standard car's 0-62mph sprint time of 4.4 seconds, as well as its 155mph top speed.