Nicole Scherzinger hints at Girls Aloud reforming

The 32-year-old former Pussycat Doll also slammed reports that her Formula One star boyfriend Lewis Hamilton has proposed as 'ridiculous'.

Nicole also compared fellow X Factor judges Simon Cowell and Paula Abdul to singing stars Sonny and Cher because of their 'great chemistry'.

Nicole, now promoted from host to fully-fledged judge on the US X Factor at Cheryl's expense, was interviewed over the phone by Aussie radio hosts Kylie Sandilands and Jackie O for their Sydney breakfast show.

Asked to give the reasons for Cheryl's US X Factor departure, Nicole said, 'I have no idea.

'I think she made the decision ultimately for herself, I heard that maybe Girls Aloud are going back on tour.'

Nicole also said she was better served being a judge on the show rather than a host.

'I did start out as a host and then they asked me to be a judge, I felt like I was better served as a judge, I could mentor and have a voice,' she said.