The well-known equation of Russian oligarch wealth tells us that the more money they have in the bank, the more flash cars, yachts and football teams they will buy.

But while your average billionaire has a collection of Ferraris, Porsches and Bugatti Veyrons - an unnamed Russian oil magnate has bought a car more controversial than Jeremy Clarkson doing the school-run in a stretch Hummer.

The unnamed billionaire (wise use of anonymity) has just snapped up a car used by Adolf Hitler to travel across Europe during World War 2 - for an estimated £5 million.

Fichael Froehlich, a Duesseldorf car dealer, brokered the deal for the mystery Russian, who also bought other vehicles from a collection which included seven more cars used by Nazi leaders.

The £5m price-tag was no doubt driven up by photos showing Hitler in the midnight blue Mercedes 770 K, licence plate number 1A 148461 - part of a fleet used by the fast and the Fuhrer. Get it?

Since the end of the Second World War the car has had several owners including a museum in Las Vegas, a German brewery tycoon and various car collectors.