Whether it's an alleged sex tape with ex-beau Jason Wahler or reports that some of The Hills' scenes are fake, Lauren "L.C." Conrad is no stranger to refuting rumors.

So when her former Laguna Beach rival Kristin Cavallari was rumored to be joining the cast of The Hills, Conrad and BFF Audrina Patridge had to put that one to rest during Extra's Monday night broadcast.

"[That's] false... when we heard about it, we called [the] producers..." Conrad told Extra before being cut-off by Patridge.

"... And they said no," said Patridge, finishing Conrad's sentence.

Last month, an "inside source close to The Hills" told E! News that the show's producers were "looking into the possibility of bringing" Cavallari onto the series.  At the time, MTV had issued a statement that they could not confirm that Cavallari would be joining the show's cast.

Cavallari and Conrad first met as students at Laguna Beach High School -- where Cavallari was a junior and Conrad a senior -- and both regularly appeared as Laguna Beach cast members when the MTV reality series premiered in Fall 2004.  However they were never friends, as Cavallari was dating Conrad's long-time childhood friend Stephen Colletti.

Cavallari and Colletti's relationship eventually fizzled.  Ironically, Cavallari then dated The Hills star Brody Jenner, who Conrad currently has a coy romantic relationship with.

While Conrad moved to Los Angeles and appeared in Laguna's The Hills spin-off, Cavallari started acting in the scripted genre with cameos in Veronica Mars and Cane as well as roles in such films as Fingerprints and Spring Breakdown (which she is currently filming). 

Cavallari's only unscripted work since Laguna was on the now-defunct UPN when she served as co-host for Get This Party Started, where she worked with professional party planners to throw bashes for deserving people at significant points in their lives.  The show premiered in January 2006 and was subsequently canceled after airing only two episodes.