The British luxury carmaker has revealed that it will publicise some of the most gruelling parts of the Cullinan's testing programme through its new deal with television channel National Geographic.

The luxury model has been testing for three years in Northern Europe, the Middle East and the United States. As part of RR's deal with National Geographic, the Cullinan will now be filmed and photographed as part of the 'The Final Challenge' series, which will be posted on social media.

The Cullinan, due for launch later this year, is claimed to mix ultra-luxury with genuine off-road ability. Rolls-Royce unveiled the car's pop-out, tailgate-mounted seats and table recently, following confirmation of the car's name. Recent spy shots showed the Cullinan with the least disguise we've seen yet, revealing a lot of the Phantom-like look of the car. The pop-out seats are rear-facing and intended for use while the car is not in motion; each of them bears the Rolls-Royce logo and both fold back into a compartment in the boot floor.

The Phantom's design influence is clear to see, with a near-identical fascia at the front and D-shaped tail-lights at the rear. The boxy design shows that the Cullinan takes after the Phantom rather than the smoother-looking Ghost. Spy shots show that the rear doors are rear-hinged, as seen on both the Ghost and the Phantom.

The rival to the Bentley Bentayga was called 'Project Cullinan' during its development. The name is inspired by the Cullinan Diamond – a 3,106-carat jewel extracted from a South African mine in 1905. The diamond was split into nine stones, with the two largest stones used in the British imperial crown and the Sovereign’s Sceptre with Cross. Rolls-Royce boss Torsten Müller-Ötvös said the Cullinan name had been “hiding in plain sight.”

“It is the most fitting name for our extraordinary new product,” he added.

The Cullinan – which Rolls-Royce refers to as a 'high-sided vehicle' rather than an SUV – is likely to use a developed version of the Phantom’s 6.8-litre V12 engine. A plug-in hybrid powertrain could also be offered at a later stage, using technology from parent company BMW. Rolls-Royce has dismissed a diesel option due to the comparative lack of refinement offered by such units.

The all-wheel-drive car will use the same aluminium spaceframe platform as the Phantom, called the 'Architecture of Luxury', by the automaker.