It will top the range of the third-generation X6, which is expected to make its bow at the Shanghai motor show next April.
Production will remain at BMW’s Spartanburg plant in South Carolina, US, where prototypes are already being built for testing. A regular X6 prototype was also spotted on the same outing as the pictured X6 M.
The X6 range will kick off with xDrive30d and xDrive40d variants, although a greater petrol-powered offering is expected. xDrive40i, 50i and 45e versions will make up the rest of the range, with the notable addition of the plug-in hybrid.
M Performance M50d and M50i variants are also planned as BMW proliferates its M sub-brand, although the M50i petrol might not be offered in Europe, as it's geared towards the US market.