Los Angeles - Nicki Minaj allegedly threatened Mariah Carey by shouting: "Off with your head!"
The American Idol judges' explosive argument was caught on camera on Tuesday and shows Nicki screaming violent insults at Mariah because she made her feel "inadequate" during the auditions round of the competition.
The video, obtained by TMZ, shows Nicki firing an X-rated string of accusations at Mariah, despite fellow judges Randy Jackson and Keith Urban trying to diffuse the heated fight.
TMZ also claimed a show insider overheard Nicki taking her threats to the next level by ranting: "If I had a gun, I would shoot her."
In the video Nicki shouts: "Think I'm playin? Think this shit is a fucking joke? Think it's a joke?... If you say one more disrespectful thing to me - off with your head!"
Mariah replies: "I am not being disrespectful", to which Nicki retorts: "Off with your head, off with your head.
"Don't tell me I'm insecure, don't tell me I'm inadequate ... You're the insecure one sitting up there running down her resume every five minutes.
"I told them, I'm not fucking putting up with your fucking highness over there ... Figure it out."
Show bosses called off filming in Charlotte, North Carolina so the stars could cool off, but there are fears the newly-appointed judges will be unable to work together in future after Mariah branded Nicki immature and the feisty rapper slammed the diva for being "boring as fuck".
The video ends with Mariah whining: "Why do I have a three-year-old sitting around me?... I can't see my kids because you decided to have a little baby fit and going all around the stage."
Nicki retorts: "Good, well then go see them now, go see them now ... you're boring as fuck."