Rita Ora has secretly been working on a new song with Chris Brown.

The 'How We Do' hitmaker - who famously doesn't get along with Chris' ex-girlfriend and 'American Oxygen' singer Rihanna - has reportedly been working with the 26-year-old star on some new material.

A source told The Sun newspaper: ''Rihanna's always been wary of Rita. They have a similar image and there's hardly a big difference in their music. The song with Chris sounds amazing and is bound to be a big hit. It's the best song Rita's done and will break her in the US.''

The 24-year-old beauty - who previously dated her 'I Will Never Let You Down' collaborator Calvin Harris - is said to be hoping working with Chris will boost her profile across the pond but it will also likely add to the tension between her and Rihanna, who are both signed to Jay Z's Roc Nation label.

The track on which the 'Loyal' hitmaker is rumoured to feature will appear on her new album and is expected to follow her latest song 'Poison' as a single.

Meanwhile, Rita is currently in negotiations to join Simon Cowell, Cheryl Fernandez Versini and Radio 1 Breakfast Show DJ Nick Grimshaw on the judging panel for the next series of 'The X Factor', despite having only completed one series on rival show 'The Voice' earlier this year.

A source shared: ''Simon likes that Rita will keep Cheryl on her toes.''