Kristin Cavallari's Brother Michael Found Dead, Police Say

— -- Days after news broke that Kristin Cavallari's brother Michael was officially categorized as a missing person by authorities, police believe they found his body.

"At approximately 10:30 a.m. search crews located remains believed to be that of Michael Cavallari. At this time, the body is being transported to the Office of the Utah Medical Examiner for positive identification and to determine the cause of death," The Grand County Sherriff's Office in Utah said in a press release on Thursday.

The release added, "The terrain where the body was located is a steep and very rocky area."

Cavallari herself added in an Instagram post, "My heart is in a million pieces. Mikey, I could always count on you to make me laugh. You had such a good heart and will be forever missed. I'm at a loss for words but I know u are in a better place and finally at peace. I love u so much RIP."

Michael went missing shortly after Thanksgiving and his car was found abandoned by Utah authorities, according to the Grand County’s Sheriff’s Office.

"At this time, the Grand County Sheriff's Office is handling this matter as an active missing person investigation," authorities wrote on the office's official website on Dec. 5.

Shortly after news broke of her missing brother, Kristin Cavallari, 28, took to Instagram and said she remained "hopeful" that he would be found alive and well.

"I appreciate all the concern, thoughts, and prayers that have been extended to me and my family," she wrote on the social media site. "We remain hopeful and I will share any news that we receive. I have such gratitude for all those that have shared their support."

Cavallari, who is the mother of three with husband Jay Cutler, rose to fame more than a decade ago when she starred in the MTV show "Laguna Beach" and its spin-off "The Hills."

A request for comment from Cavallari's rep was not immediately returned to ABC News.