Former "American Idol" judge Simon Cowell and Pussycat Doll lead singer Nicole Scherzinger's fight goes on in the recent episode of the U.S. version of "X-Factor". But the feud went beyond the judging in the show.

According to RadarOnline, Cowell was nosing in where was not supposed to by co-mentoring Nicole's team for Wednesday night's show. It is noticeable that Cowell is overly critical of Nicole's contestants.

The feud of the two "X-Factor" judges is now personal.

We witnessed how the two exchanged sarcasm during the two and a half hour special episode of the "X-Factor." wherein, the 33-year-old voluptuous singer was claimed to be furious with Simon's constant criticism.

There are reports that Nicole and Simon are at each other's throats and criticize each other and their contestants even over minor details.

It is unclear when the Simon-Nicole feud started. It may have been when reviewers preferred Cheryl Cole over the Pussycat Doll darling. There was a time in the two-and-a-half hour show when Nicole looked straight at the camera and said sarcastically, "Thanks a lot for the support right now, Simon. It's the first live show. Awesome."

Simon gave a backhanded insult to Nicole when he criticized the contestant Dexter by saying, "You're interesting and you're unpredictable, much like your mentor."

Simon criticized Nicole's protégés such as Stacy Frances and LeRoy Bell.

Simon is very much on-hands with his contestants. Nicole increased the security for her contestants after they were mobbed in their trip to the mall. Moreover, he ordered his personal bodyguards that they never leave the studio by themselves.

Last night is the first night that the viewing public is allowed to vote and part of the staying power is to win over the audience.

With Nicole's recent breakup with her boyfriend for four years - F1 driver Lewis Hamilton, she looked heartbroken on her recent trip to London for the performance of her single "Try With Me" on the UK version of the "X-Factor."

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According to sources, Simon Cowell will return on the show next year and hopes that Barbara Windsor and David Williams will join the panel.

Judge Nicole Scherzinger poses at the world premiere of the television series "The X Factor" at the Arclight Cinerama Dome in Hollywood, California September 14, 2011.

Simon Cowell poses at the world premiere of the television series says the British version needs to: "Sort it Out" after losing more than two million viewers.

Judge Nicole Scherzinger poses at the world premiere of the television series "The X Factor" at the Arclight Cinerama Dome in Hollywood, California September 14, 2011.

"X Factor" judges are receiving death threats after the most recent elimination.