One Direction have hired Grant Thornton, the company that looks after all the National Lottery big-money winners, to look after their finances after accumulating an estimated personal wealth of £15million each. In two years.

“Their success is quite staggering – so are the profits coming with it. The lads had an incredible 2012 and this year looks even bigger,” a source told The Mirror.

“Although they’re all mature for their age, they are still five young boys at heart, and have all made mistakes – it’s part of growing up. They’ve now been assigned a small team at one of the country’s top money service providers who will be advising the boys on matters of tax, capital and investment.”

Apparently, the move was the idea of the boys’ record label, Syco, who are fearful the band will get swept up in the hype of their intense fame.

“One Direction have become one of Sony’s biggest draws and the label wants to make sure the guys are looked after,” a source added.

This is not to say the boys won’t be allowed to splash out a little now that the band have developed some fine tastes.

Liam shelled out £13,000 on a Hublot watch. The 19-year-old also treated on-off girlfriend Danielle Peazer to a £50,000 Audi TT for her birthday.

Louis and Harry are car-mad. Louis, 21, owns a £45,000 Porsche and a £90,000 Range Rover.

Harry, 18, owns a £100,000 Audi R8 Coupe, a £60,000 Range Rover and an £80,000 classic Porsche.