Mariah Carey is facing a $20 million (£16m) lawsuit for copyright infringement over her iconic song All I Want For Christmas Is You.
The five-time Grammy award winner and her co-writer Walter Afanasieff are both being sued by songwriter Andy Stone, who claims he co-wrote a track with the same name in 1989.
In legal documents filed in Louisana, Mr Stone states he has never given permission for the song to be used and claims Ms Carey and her collaborators "knowingly, wilfully, and intentionally engaged in a campaign" to infringe his copyright.
He has also accused them of acting in a way that was "designed to exploit the popularity and unique style" of his song, adding that it "caused confusion", according to the court documents.
The two songs have different lyrics and melodies.
The suit goes on to accuse the defendants of committing "acts of unjust enrichment by the unauthorised appropriation of plaintiff's work and the goodwill associated therewith".
The lawsuit adds that Mr Stone is seeking damages of $20 million (£16 million).
Released by Ms Carey on her 1994 album Merry Christmas, the song has gone on to become one of the most well-known festive hits and has been streamed more than one billion times on Spotify.
The album also saw great success, becoming the best-selling US Christmas album of all time, with more than 15 million copies sold worldwide.
Representatives of Mariah Carey have been contacted for a comment.