Tulisa is furious after rival talent show judge will.i.am took one of her songs and reworked it - adding Britney Spears' vocals to the track.
Tulisa originally recorded new single Scream & Shout, which was then charmingly called I Don't Give a F**k, after co-writing it with will's pal Jean Baptiste, and she had included it on some early versions of her album The Female Boss.
But after it was dropped from the record, will enlisted the help of Britney to re-record a new version - which is now headed for number two in the UK charts.
A source told the Sun: "The song was due to be Tulisa's third single from her album until Will told his protege Jean that he wanted the beat for him and Britney. Tulisa's team thought it was a surefire hit but, after losing the battle for the rights, they were forced to release Sight of You which only got to number 18."
The insider added: "At one point Tulisa was even considering releasing her version to rival Scream & Shout, but now it's unlikely to see the light of day unless it gets leaked."
The reports go some way to explain why Britney is putting on an odd London accent in the track - it appears she was trying to emulate Tulisa's style.