X Factor winner Matt Cardle has distanced himself from a multi-million-pound lawsuit between his songwriters and Ed Sheeran.
Ed is being sued for more than £13 million by songwriters Martin Harrington and Thomas Leonard.
They allege that his 2014 summer hit Photograph copies Matt's 2012 single Amazing, which they wrote, and that the songs' similarities "reach the very essence of the work".
Matt tweeted his respect for Ed and reminded fans that "this is not my lawsuit".
Lawyer Richard Busch, who recently triumphed on behalf of Marvin Gaye's family in a copyright case over the Robin Thicke hit Blurred Lines, is representing the songwriters.
According to court papers posted online, the lawsuit alleges that the choruses of Amazing and Photograph share 39 identical notes.
It reads: "The similarities go beyond substantial, which is itself sufficient to establish copyright infringement, and are in fact striking.
"The similarity of words, vocal style, vocal melody, melody and rhythm are clear indicators, among other things, that Photograph copies Amazing."
The parallels are also said to be "instantly recognisable to the ordinary observer", with the songwriters saying the alleged copying makes up "nearly one half" of Ed's single.
Ed will have to answer the charges alongside his Photograph co-writer, Snow Patrol's Johnny McDaid, as well as other co-defendants including Sony/ATV Songs, Warner Music and Polar Patrol Music Publishing.
The plaintiffs claim that the team behind Photograph, which was nominated for a Brit award and is also featured on the soundtrack for new movie Me Before You, were aware of Matt's single.
The lawsuit states: "Given the striking similarity between the chorus of Amazing and Photograph, (the) defendants knew when writing, publishing, recording, releasing, and distributing Photograph that they were infringing on a pre-existing musical composition.
"The conduct of (the) defendants has been wilful from the inception of the creation of Photograph."
Here are the two songs to compare:
The lawsuit states that the defendants had already been given notice of the complaint, but it had not been resolved before papers were filed at court.
The songwriters have asked to be awarded the profits on the song, which are believed to be more than 20 million dollars.
A permanent injunction is also sought on Photograph, which could prohibit Sheeran from performing the song in future or selling recordings. If this is not possible, the plaintiffs are seeking royalties.
Last year, a jury determined that Robin Thicke and Pharrell Williams had copied Marvin Gaye's 1977 hit Got To Give It Up.
Gaye's children were awarded nearly £4.9 million, after a trial which had focused on detailed analyses of chords and notes in Blurred Lines and Gaye's song.