Nicki Minaj freak-out 'Mariah's fault'

Los Angeles - Nicki Minaj threatened Mariah Carey after her American Idol co-star reportedly called her a bitch, reports Mouthtoears.com.

Show bosses cancelled filming in Charlotte, North Carolina for the day after a huge blow up between the pair.

Witnesses say that Nicki threatened Mariah and lost her temper while cussing at her.

A source told Mouthtoears.com: "Nicki Minaj walked off of set because Mariah Carey kept making jabs at her. Nicki's manager and team convinced her to come back to the show. Mariah kept at it and called Nicki a bitch and then proceeded to cuss her out. Producers had to stop filming and call it a night."

'I'm going to knock you out'

It was previously revealed Nicki fumed she was sick of her co-star's "fucking highness" and their fellow panelists Keith Urban and Randy Jackson were caught in the middle of the fight.

A source told TMZ: "Nicki said to Mariah: 'I'm gonna knock you out'. Nicki added 'I told them, I'm not fucking putting up with her fucking highness over there'."

According to insiders, producers are now concerned about how the pair will manage to work together for the rest of the season.

Watch Nicki Minaj's freak out at Mariah Carey here: