The Script are suing X Factor winner James Arthur for copyright infringement over his single Say You Won't Let Go.
The Dublin band claim that Arthur's 2016 comeback single is too similar to their hit The Man Who Can't Be Moved, which was released in 2008.
Their lawyer Richard Busch filed the suit against James Arthur in Los Angeles County Superior Court on Monday and claims his song rips off The Man Who Can't Be Moved, which was written by Danny O'Donoghue, Mark Sheehan, Andrew Frampton and Stephen Kipner. A number of other co-defendants are also named in the suit.
Busch, who is filing the claim on The Script's behalf, previously represented Marvin Gaye's estate in its lawsuit against Robin Thicke and Pharrell Williams over the song Blurred Lines, which Gaye's estate claimed was too similar to Gaye's 1977 hit Got to Give It Up.
The Gaye estate won $5.3m and half the royalties.
When Say You Won't Let Go was released in 2016 fans immediately noted its similarities to The Script song. According to Billboard they include the same 4/4 meter, tempo, four bar guitar intro and vocal melodies.
In a statement released to Billboard, Busch claimed that Say You Won't Let Go gave Arthur "worldwide success" after he had been dropped by his record label for a series of controversies.
According to TMZ, Busch claims, in the suit, that Arthur had allegedly approached The Script to collaborate on a track in 2014 but they declined.
Arthur denies the claims. Last year he told The Sun that there was "no case to answer" regarding similarities between the songs, adding, "It's 2017, there's only seven notes in music.
"Every blues song sounds the f***ing same. People get wound up about these things for no reason."
Both James Arthur and The Script are signed to the same management company.