R&B singer Devin Copeland, known professionally as De Rico, and songwriter Mareio Overton filed a lawsuit last week in U.S. District Court in Virginia alleging that they came up with the song "Somebody to Love."
Bieber, who is managed by one of Usher's business ventures, released "Somebody to Love" in 2010 with Usher also singing on the recording. The song peaked at No. 15 on the U.S. Billboard chart.
Copeland and Overton allege that "Somebody to Love" has the same title, time signature, underlying beat pattern as well as similar chords and share similar lyrics, including the chorus "I ... need somebody to love."
"There is essentially a zero probability for the number of points of congruence between the two versions of 'Somebody to Love,'" Copeland and Overton said in the lawsuit.
Bieber, songwriter Heather Bright and the Stereotypes are credited as the writers of Bieber's "Somebody to Love."
Messages left with attorneys for Bieber and Usher were not immediately returned.
Copeland and Overton allege that music scouts presented "Somebody to Love" to Usher in 2009, and that Usher's mother, who also serves as his manager at times, asked Copeland to re-record the song and go on tour with Usher.
After not hearing back from Usher, Copeland alleges in the lawsuit he heard his song being sung by Bieber on the radio.
Usher, who first recorded the song as a demo for his 2010 album "Raymond v. Raymond," later recorded a remix version with Bieber singing backing vocals on the song.
The lawsuit lists 19 defendants, including record label Universal Music Corp, a unit of French media company Vivendi.
(Reporting by Eric Kelsey; Editing by Jill Serjeant and Eric Walsh)