Two musicians based in California are suing Ed Sheeran for $20m (£13.8m) over his single Photograph.
British songwriter Martin Harrington and American Thomas Leonard claim the track has a similar structure to one of their songs.
The two musicians allege Ed Sheeran’s ballad, released as a single in 2015, has the same musical composition to their song Amazing.
Martin Harrington and Thomas Leonard say they wrote their track in 2009.
Harrington and Leonard’s song Amazing was adapted into a single of the same name for Matt Cardle, the winner of The X Factor in 2010.
Matt Cardle’s version of the track has more than one million views on YouTube, while Ed Sheeran’s music video for Photograph has 208 million.
Martin Harrington and Thomas Leonard are using the same lawyers who won a case for the family of the late soul singer Marvin Gaye.
They successfully sued Robin Thicke and Pharrell Williams for copyright infringement last year over their Blurred Lines, winning a $7.4m (£5.1m) settlement.
Documents in the copyright infringement case were filed on Wednesday.
Other named defendants being sued include Snow Patrol’s Johnny McDaid, who is credited as a co-writer on Photograph, as well as various divisions of Sony/ATV Music Publishing, Warner Music Group and its subsidiary, Atlantic Recording Corporation.
Harrington and Leonard, and their publishing company HaloSongs, want a trial and damages of more than $20m (£13.8m), as well as royalties from the song.