"It's no big secret that Nicole and I are no longer friends," Hilton said.
"I will not go into the details of what happened. All I will say is that Nicole knows what she did and that's all I am ever going to say about it."
E! News reported last week that the former pals are so on the outs that Hilton is trying to convince Fox suits to recruit Kimberly Stewart to costar with her on The Simple Life 4.
Stewart, rocker Rod Stewart's daughter and a fixture on the L.A. party circuit, showed up arm-in-arm with Hilton to an Us Weekly event last Wednesday and dropped big hints about the impending Simple Life shakeup.
"We've known each other since we were in our moms' tummies," Hilton told E! at the party. "When you're with your friend you've known your whole life, you totally trust them. We just act like sisters...we have fun."
When asked about her rift with Richie, the hotel heiress was diplomatic.
"You know, I've had three great seasons [on the Simple Life]," Hilton said. "I love the show, and I just want to freshen it up and make it funnier and bring new things in," she said. "It's going to be a big surprise. And everyone is going to be very excited and happy about it."
With Hilton reportedly ready to be paired off with a new Simple Life lady, Richie would, per reports, get her own reality spinoff, a Newlyweds-esque endeavor focusing on her life with soon-to-be hubby Adam Goldstein, aka DJ AM.
Richie was also at the Us Weekly party Wednesday, supporting her fianc who was spinning at the bash, but declined to talk to reporters and did not talk to Hilton. Her publicist has so far refused comment on the rift or her rumored new show.
And Fox suits aren't saying anything specific about the possible Simple Life switcheroo. However, the network did issue a statement alluding to potential changes.
"We are currently discussing internally the creative direction of the next season of The Simple Life," the network said Thursday.
"We are huge fans of both Paris Hilton and Nicole Richie and look forward to solidifying our plans for the next installment of this fantastic franchise in the very near future."
There have been various rumors regarding the nature of Richie's never-to-be-uttered sin against Hilton. The leading theory concerns a prank gone bad at Paris' sister Nicky's apartment, where a group of pals had gathered to watch Paris' Saturday Night Live hosting debut from February only to be surprised when someone (Richie, perchance?) swapped out the SNL tape with Hilton's XXX opus One Night in Paris.
Reports have been swirling since last summer that Hilton and Richie were on the outs following some off-camera meltdowns while shooting the second season of The Simple Life.
Hilton and Richie downplayed any animosity, though, eventually signing on to do the currently airing third season of their fish-out-of-water hijinks, The Simple Life: Interns.
Interns debuted with the series' best-ever ratings--13.3 million viewers. Although those numbers have steadily declined in recent weeks, the show averages a still healthy 10.2 million on Wednesdays opposite ABC's new hit, Lost.
Fox has enough confidence in The Simple Life to move the show to Thursdays starting next week. The scheduling move, to last just three weeks, will pit Paris and Nicole against final episodes of NBC's The Apprentice and CBS' ratings powerhouse CSI during the May sweeps.
Nicole doesnt seem very enthused this season though so i do wonder if shes had it with this whole simple life stuff. she barely seems to fake an interest and sometimes i'm not even convinced shes awake at all. until a 'sada sa' breaks lose, shes certainly not into anymore
and he said to me: do not seal up the words of the prophecy,for the time is near behold, I am coming soon