The annual Stagecoach music festival in Indio, CA, has become a storyline on Bachelor in Paradise in recent years due to the fact many The Bachelor and The Bachelorette alums attend the event and mix and mingle.
On Monday night's episode of Bachelor in Paradise, Kira told her pal Genevieve Parisi that Justin and Salley had been "all over" each other at Stagecoach in April, with Justin allegedly "macking" on the blonde beauty and igoring everyone else.
Justin fired back at the allegations on Twitter earlier this week, claiming Kira's story was "news" to him and he didn't even know the physician -- whom he said would do "anything for some screen time" -- was at Stagecoach to begin with.
"I'm friends with a couple of the girls who went to Stagecoach. I can back Kira up," Jill toldUs Weekly on the latest episode of its "Here for the Right Reasons" podcast.
"Kira, I'm with you here, girl. You were at Stagecoach and Justin was there," Jill confirmed.
Jill went on to say, "And I heard very similar stories to what Kira was saying. But I don't want to discredit Justin's experience. I just want to say I've heard that as well. There could be hearsay, but I do trust my friends."
Jill admitted she hasn't spoken to Kira since filming Bachelor in Paradise -- during which drama went down between Romeo Alexander, Kira and herself -- but she insisted she was really good friends with Kira before the show.
Salley has yet to make an appearance on Bachelor in Paradise's eighth season, but bartender Wells Adams teased on an episode earlier this week that she'll be arriving at the beach soon.
In light of some backlash from Bachelor in Paradise fans, who have accused Kira of gossiping and starting unnecessary drama, Kira wrote to her followers, "I didn't tell Genevieve about Salley to rattle her."
"I told her the cold, hard facts so she can have the full picture before she decides how she feels about Justin," Kira added. "Sometimes being a good friend means having difficult conversations. #BachelorInParadise #BachelorInParadiseABC."
Salley has yet to address the scandal and share her version of events.
Salley has been a mystery to Bachelor Nation since she only appeared in one episode of Clayton Echard's The Bachelor season and quit before making a limo entrance on Night 1.
Wells also claimed the previously-engaged bachelorette sent her suitcase to Mexico without ever boarding the plane due to unresolved issues with her former fiance.
Wells poked fun at Salley's complicated and emotional journey to Paradise in a story he dubbed "The Saga of Salley's Suitcase."
Wells' saga, which he shared with several bachelorettes on Monday night's episode, included explosive diarrhea, a producer waiting for Salley in the trunk of a car for four hours, and Salley allegedly being totally hung up on her ex.
Wells wouldn't confirm or deny how much of his story about Salley was actually true in a Tuesday interview with Entertainment Tonight.
Bachelor in Paradise's eighth season currently airs on Monday and Tuesday nights at 8PM ET/PT on ABC.