Cardi B's former manager is suing her for breach of contract and has filed a $10m (£7m) lawsuit against her.
Klenord "Shaft" Raphael says he is "disappointed" the rapper has frozen him out of her career.
He's accused Cardi B, who signed with a new management company in March of "breach of contract, unjust enrichment and defamation".
Cardi B, who's now one of the hottest properties in hip hop, has yet to respond to the claims.
Cardi B and Klenord Raphael started working together in 2015. He's also listed as a writer and producer on her hit debut single, Bodak Yellow.
But a full statement from his KSR management company read: "Since discovering Cardi B in 2015, Shaft has played an integral role in developing her music career and public image.
"While he is proud of their successful collaborations as she evolved from Instagram influencer to music megastar, Shaft is disappointed by her actions to freeze him out of her career, which are detailed in the complaint.
"Shaft is confident that his lawsuit will validate his conduct and substantiate his legal claims."
His social media feed is full of videos and pictures which include insights into the early days of Cardi B's career.
Cardi B who released her debut album Invasion of Privacy in April 2018 is currently signed to Quality Control management.
The 25-year-old signed with them in March - but the lawsuit claims this breeched the terms of her deal with KSR management.
Since the release of her album, Cardi B has shattered records including becoming the first female artist with 14 songs on Billboard's Hot 100 Charts.
The previous record was held by Beyonce who had 12.
Her rise to the top of the charts is impressive.
Originally from the Bronx in New York, Cardi B has spoken about becoming a stripper in her teens to escape an abusive relationship.
She said the money she made from stripping also helped her pay for school.
Cardi B performs with Ozuna at the 2018 Billboard Latin Music Awards
Cardi B recently announced she was taking a break from performing live - a month after confirming she was pregnant.
The rapper, who's dating Offset from Migos, told her fans via an Instagram video: "Broccoli Festival will be my last performance for a while because you know the baby keeps growing.
"I'll be looking like I am moving on stage okay, but the reality is shorty keep growing and sometimes I can't breathe. I will be back for the Bruno Mars tour though."
Cardi B or her record label are yet to respond to the claims.