Britney Spears is rumoured to be making an appearance on Madonna's new album.

An album sleeve has apparently been leaked - and is pictured on Britney fansite BreatheHeavy.com - which suggests the pop princess will feature on Madge's track Girls Gone Wild, the lead song on her upcoming MDNA album.

However, it isn't known whether the artwork is authentic and neither camp has commented on the speculation.

Britney, 30, and Madonna, 53, have worked together several times, starting when they famously locked lips on stage at the VMAs in 2003.

After that, Madonna featured on Britney's song Me Against The Music and Britney joined the Queen of Pop on stage in LA during her Sticky And Sweet tour in 2008.

MDNA will be released next month.