An odd-looking Volvo XC90 prototype has been spied in Europe, sporting a very long wheelbase and scaffolding over the tailgate.

The red prototype features a rear axle that is noticeably further back than the standard XC90, with photographers estimating the wheelbase on this vehicle has been stretched by nearly 250mm – for reference, the XC90 has a 2984mm wheelbase.

Also featuring on this test vehicle is a very solid steel platform that has been built over the rear of the car, which is believed to provide extra stability.

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Initially it was thought this mule is an early prototype for a larger SUV model or a long-wheelbase version of the XC90, though there has been no word of such a project so far.

Another possibility is that Volvo is working on a 4x4 ute to take on the upcoming Mercedes-Benz X-Class.

It's unknown what exactly this Volvo prototype is, so we'll have to wait and see if it starts to drop the XC90 disguise as it progresses through its development.

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What do you think is under the skin of this Volvo XC90? Let us know in the comments below