(Cover) - EN Showbiz - Nicki Minaj has been caught on camera cursing at Mariah Carey.

There has been speculation the pair have had a strained relationship since they joined the judging panel for American Idol. In new footage obtained by TMZ, a furious Nicki is seen shouting at Mariah and allegedly even threatened to "knock out" her fellow judge before the video started.

The incident took place during auditions in Charlotte, North Carolina, on Tuesday, after they apparently disagreed over a contestant's performance. Other reports suggest Nicki lost her temper because Mariah was "making jabs" at her.

Although the audio is difficult to hear, Nicki is seen looking at Mariah and pointing angrily as she claims she is being "patronised".

"I told them, I'm not f**king putting up with her f**king highness over there. Figure it out," she shouts. "I'm not gonna sit here every f**king minute to have you come down and harass me every minute every day."

She also repeatedly says, "Don't lose your head," during the clip before snarling, "Don't tell me I'm a gangster".

Fellow new judge Keith Urban is seen looking uncomfortable as he sits between the pair and head judge Randy Jackson warns them to "settle down".

During the disagreement Mariah appears to bring up the subject of her children, saying she would rather be spending time with them than fighting with Nicki.

Auditions are believed to have ended for the day after the argument, to allow Nicki and Mariah time to cool down. (C) Cover Media