Nicki Minaj threatens Mariah Carey?

Yikes!

The showdown between newbie "American Idol" judges Nicki Minaj and Mariah Carey may be even nastier than we thought.

After video surfaced this week showing Minaj and Carey throwing insults at each other (reportedly stemming from different opinions of a contestant's performance), a new report is claiming that Minaj made a death threat against Carey, which was not caught on the tape.

According to TMZ's sources, in the heat of the argument, Minaj said: "If I had a gun I would shoot her."

Meanwhile, "Idol" bigwig Nigel Lythgoe refuted the claim, telling TMZ" The statement [that Nicki made a death threat]is absolute rubbish. It's absolutely not true in any way, shape or form."

He added that when Carey confronted Minaj about the alleged threat - which she heard about through her "people" - Minaj said she "absolutely" did not make the gun comment.