Kristin Cavallari continues to expose some dirty secrets of "The Hills" -- saying her costars were bribed to lie about her!
In the show's final season premiere, Stephanie Pratt, Lo Bosworth and Audrina Patridge were all seen confronting KC about her hard partying at the Super Bowl ... something she claims was set up by a sneaky producer.
"What happened was, one of the producers told the girls he would give them gifts ... specifically a Birkin bag, if they talked about me doing drugs on camera," Cavallari alleges in a new interview with E!'s Giuliana Rancic.
"The girls took the bait and the next thing I know, we get home and it's in the tabloids that I have this huge drug problem and I need to go to rehab," she adds.
Cavallari says the entire scenario made her feel "so used" and she believes the producer had "taken it too far."
So ... did the girls end up getting those pricey bags? Watch the video above to find out.
Cavallari says MTV wasn't aware of the producer's actions. A rep for the network wasn't immediately available for comment.