The fully produced version of the song comes from Spear's 2013 album, "Britney Jean," and now Orbit, who produced the album, has posted a message online giving his explanation on why her voice sounds the way it does on the leaked version.

Orbit posted the following message on Facebook, "Dearest Music Lovers, I have heard that Britney vocal link that everybody's been discussing. It has been impossible not to as there have been many comments directing my attention to it. [I won't re-posting it here]. I'd like to affirm that ANY singer when first at the mic at the start of a long session can make a multitude of vocalisations in order to get warmed up.

"Warming up is essential if you're a pro, as it is with a runner doing stretches, and it takes a while to do properly. I've heard all manner of sounds emitted during warmups. The point is that it is not supposed to be shared with millions of listeners.

"A generous singer will put something down the mic to help the engineer get their systems warmed up and at the right level, maybe whilst having a cup of herb tea and checking through lyrics before the session really kicks off. It's not expected to be a 'take'.

"I think that 99% of you reading this will totally understand. Whomever put this on the internet must have done so in a spirit of unkindness, but it can in no way detract from the fact that Britney is and always will be beyond Stellar! She is magnificent! And that's that."