Mariah Carey has been cleared of copyright infringement in a case over her 1994 Christmas staple, All I Want for Christmas is You.

In a ruling issued on Wednesday, a US judge rejected the allegations of songwriter Adam Stone, who released a song with the same name in 1989. He accused Carey of exploiting his "popularity" and "style".

Mr Stone, who performs under the name Vince Vance, was claiming at least $20m (£16m) in damages.

But in her ruling, Judge Mónica Ramírez Almadani cited expert testimony saying the two songs simply shared "Christmas song clichés" that were common to several earlier hits.

Mr Stone and his lawyers had not "met their burden of showing that [the songs by] Carey and Vance are substantially similar", she wrote.

Judge Almandi also ruled that Mr Stone and his lawyers should face sanctions for filing "frivolous" arguments, that included "vague... and incomprehensible mixtures of factual assertions and conclusions, subjective opinions, and other irrelevant evidence".

She ordered Mr Stone and his lawyers to repay the legal bills Carey incurred in defending the case.

The case was originally filed in 2022, with Mr Stone claiming Carey's hit was copied from a song he'd recorded under the name Vince Vance and the Valiants.

In court papers, he claimed his track had received "extensive airplay" during the 1993 holiday season - a year before Carey's song was recorded and released.

In her 2020 memoir, Carey said she had composed "most of the song on a cheap little Casio keyboard", while playing the movie It's A Wonderful Life for inspiration, before completing it in the studio with her co-writer Walter Afanasieff.

But Mr Stone rejected that account.

"[Carey] palmed off these works with her incredulous origin story, as if those works were her own," he said in court papers. "Her hubris knowing no bounds, even her co-credited songwriter doesn't believe the story she has spun."

The initial complaint was dropped in December 2022, but refiled a month later.

Mr Stone had hoped to share in the song's runaway success. All I Want For Christmas Is You earns about $8.5 million (£6.6 million) every year; and has spent 140 weeks in the UK's top 100.

Carey's lawyers asked the court to dismiss the case last August, arguing that Mr Stone had failed to establish copyright infringement.

"The claimed similarities are an unprotectable jumble of elements: A title and hook phrase used by many earlier Christmas songs, other commonplace words, phrases, and Christmas tropes like 'Santa Claus' and 'mistletoe'," they wrote.

In Wednesday's ruling, Judge Almadani endorsed two reports from musicologists hired by Carey's team.

In one, New York University professor Lawrence Ferrara testified there were "no significant melodic similarities" between the two tracks.

He added he'd discovered "at least 19 songs" predating Mr Stone's track that had similar lyrical ideas - several of which were also called All I Want For Christmas Is You.

A similar report filed by the defence was ruled inadmissible - especially after its author admitted in a deposition that the melodies of the two songs were incomparable because "the rhythms are different".

On that basis, Judge Almadani ruled in favour of the motion to dismiss.

Neither Mariah Carey nor Mr Stone were immediately available for comment on the ruling.