Lizzo has denied allegations of plagiarism over her hit Truth Hurts, while giving a writing credit to the author a tweet which inspired the track.
Three men claimed to have helped write the song, which was originally released in 2017 but became a viral hit earlier this year after gaining popularity on TikTok.
It then topped the charts in the US and has become the the longest-running Billboard Hot 100 number one by a solo female rapper.
Earlier this month, two brothers, Justin and Jeremiah Raisen, and another collaborator, Justin “Yves” Rothman, said they had each had a hand in writing Truth Hurts.
Lizzo, 31, has now responded, dismissing their claims to the song and filing a lawsuit asking a judge to declare they have no copyright on the song.
The lawsuit accuses the Raisens of embarking “on an escalating campaign of harassment” against the singer, alleging they threatened to “go public unless they receive an unwarranted share of this work.”
Writing on social media, Lizzo said: “The men who now claim a piece of Truth Hurts did not help me write any part of the song.
“They had nothing to do with the line or how I chose to sing it. There was no one in the room when I wrote Truth Hurts, except me, (music producer) Ricky Reed, and my tears.”
Lizzo’s lawsuit, filed in federal court, says she was inspired to write Truth Hurts by a popular internet meme.
She said the line “I just took a DNA test, turns out I’m 100% that bitch” came from the meme, which Lizzo also addresses in her social media post.
She wrote: “In 2017, while working on a demo, I saw a meme that resonated with me… I later used the line in Truth Hurts… I later learned that a tweet inspired the meme.”
“The creator of the tweet is the person I am sharing my success with…”
While the star does not name the person, Mina Lioness tweeted her thanks to Lizzo shortly after the post was shared.
The lawsuit says the Raisen “expressly withdrew any claim to Truth Hurts, in writing” in April and that Rothman has never previously made the claim.
Lizzo has asked the court to enter a judgment stating the three men and their publishers have no ownership rights over the song.
She is also asking for costs and legal fees. Detroit-born Lizzo, whose real name is Melissa Vivianne Jefferson, has enjoyed a stellar year following the April release of her third studio album, Cuz I Love You.
She is also an actress and appeared in the drama Hustlers alongside Constance Wu and Jennifer Lopez.
Additional reporting by Press Association
