The X Factor champion has been accused of copying a track by Ministry of Sound producer Avicii - better known as Tim Berg - on her new single 'Collide', but has now maintained that the DJ knew about her version before its premiere on Friday.
"With regards to my song, avicii was aware & agreeing publishing splits for himself and his manager (sic)," Lewis explained on Twitter.
"When avicii sent his track out to have a song written over it I totally fell in love with this version and i think he's super talented."
Responding to the 'Happy' star, Berg stated: "Thanks for accusing me of lying and speaking on my behalf."
Berg continued: "Since we never met or even spoke, please let me and my manager know who told you that and what confirmation they gave you."
Simon Cowell's record label Syco - to which Lewis is signed - has insisted that Berg is credited as a songwriter on the track, but the producer claims that he never agreed for Lewis to use the record before its debut.
The song that Berg argues was used without his permission is known as 'Penguin', with the Swedish DJ said to have been looking for vocalists for the track over the past few months to release the song under his stage name Avicii.
Leona Lewis's 'Collide' was produced by Sandy Vee, who has previously worked with Rihanna and Katy Perry, while the track's writer is Autumn Rowe.
'Collide' will be released on September 4 in the UK.
> Can Leona Lewis's 'Collide' put her back on top?
Listen to Leona Lewis's 'Collide' below: