The blonde singer has sparked further rumours the group are to disband after confirming she is collaborating with nu-ravers Filthy Dukes for the soundtrack of forthcoming film 'Wild Child'.A friend of the star told Britain's Daily Mirror newspaper: "She was thrilled to be approached and recognised as a singer in her own right. The 'Wild Child' soundtrack is a pretty cool album with some big names on it including Rihanna, Robbie Williams and Nelly Furtado, so it promises to be a springboard to other things."
Sarah, 26, is the latest member of the band to branch out on her own, although her pal insists she is still committed to Girls Aloud.
The friend added: "She loves Girls Aloud and has no desire to for the band to split - but that doesn't mean she's not willing to expand her work."
Cheryl Cole recently provided backing vocals on will.i.am's track 'Heartbreaker', while Nadine Coyle has been dogged by rumours she wants to pursue a solo career.
'Wild Child' stars Julia Roberts' niece Emma and British actress Natasha Richardson.
