According to Martin Harrington and Thomas Leonard, their "Amazing" song shares notes attributes with the singer's "Photograph" song.
According to BBC, Sheerans 'Photograph' song has a close resemblance to their song 'Amazing', which was written for X Factor winner, Matt Cardle, in 2012.
Harrington and Leonard, presented a document that shows a close similarity between both songs.
According to the pair, Sheeran’s 'Photograph' shares 39 similar notes to their track.
The complainants have now requested damages of more than $20m and royalties generated from the song.
The lawsuit filed against the defendant reads, "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.
"The copying of Amazing by Photograph is breathtaking in its deliberateness, magnitude, and hubris."
Martin Harrington and Thomas Leonard, are using Richard Busch as their lawyer on this case.
BBC reports that Busch was the one who sued Robin Thicke and Pharrell Williams for copyright infringement 10 2015.
He reportedly won $7.4m from the case.