Bruno Mars has revealed that the current economic crisis helped to inspire one of his biggest hits.

The Sun's Bizarre column reports that the 26-year old came up with the idea for ‘Billionaire,’ his 2010 collaboration with Gym Class Heroes’ Travie McCoy, after a currency exchange during a trip to the UK that left him feeling short-changed.

Mars said: "I was in London and I wanted to exchange pounds. So I gave him $500 and he basically gave me back £200. I was like 'What?! How does this work?'

"This is how the Billionaire thing started out. I started humming it on the streets. Travie came along later and put his verses on it and then it hit the charts."

The 'Just The Way You Are' hit-maker, who has written a track for Adam Lambert’s forthcoming new album 'Trespassing', will be performing at next Tuesday’s BRIT Awards, where he is nominated for Best International Male.