Los Angeles, Sep 17  :  The four judges of US reality show "American Idol" have been finalised and announced officially. Singer Keith Urban will fill the fourth judge's position for the new season.

Following several speculations about who will be part of the popular reality show series, the final names announced are Randy Jackson, Mariah Carey, Nicki Minaj and Keith Urban, reports tmz.com.

Carey was the first person to sign the contract and Urban signed the dotted line most recently.

TV personality Ryan Searest, who will be hosting the show, confirmed the news on Twitter as he posted the picture of everyone and wrote: "It's official, your new #IdolJudges are @MariahCarey, @NickiMinaj, @KeithUrban & @Yo_RandyJackson".

This will be the 12th season of the "American Idol" franchise, expected to premiere in January 2013.

© IANS