Iggy Azalea took to Twitter to address the leak:

I happened to have noticed that pretty girls, my song with @britneyspears has leaked and is on some radio stations etc… I’m really really happy to see so many people loving it but i also just want to clarify its not an “early” release its a leak and if you can we would really appreciate everyone holding out until monday to share links etc if possible (i know its hard, I’m excited too!) Also for the record brit and i are both singing the chorus’s together… i guess you guys aren’t used to hearing my singing voice 🙂 saw some people missed that aspect, maybe when we perform it it will be more obvious hahaha.