Chart-topping group Destiny's Child are being sued for $200m (£119m) by a record producer who says they stole his music for their hit song Survivor.
Destiny's Child had a global hit with Survivor in 2001
Terrence Robinson says he gave a song called Glorious to the band's manager, the tune of which he alleges was used without his permission.
He claims the song would have given him his big break in the music industry.
Singer Beyonce Knowles' lawyer, Thomas Sulkerson, said he had not yet seen legal papers filed in Houston, Texas.
But he said the group had filed their own lawsuit against Robinson, his lawyer and a consulting company for libel, fraud and breach of contract.
Survivor was a hit around the world and won the group a Grammy Award in 2001.
Robinson, 32, from Miami, known as T-Robb, said he knew "right now I would be one of the biggest, most sought-after producers" if he had been credited.
The band's manager, Mathew Knowles - Beyonce's father - said this was the third lawsuit relating to the song.
He said: "Three people have said they have either written or did the music or the lyrics were against them, so
somebody has got to be lying."
He said Destiny's Child wrote the lyrics, while the production was handled by State of Mind Muzic's Anthony Dent.
Robinson's lawsuit also names Sony Music Entertainment, Columbia Records, Music World Entertainment and State of Mind Muzic. They did not comment.
Last year, two former members of the group settled a libel action against the R&B group over the lyrics to the hit.
Destiny's Child have not released any CDs for almost two years, but two of their three members, Kelly Rowland and Beyonce, have been enjoying solo success.