Some mysterious details have been released on the disappearance of Kristin Cavallari's brother.

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Michael Cavallari went missing over the Thanksgiving holiday after his car was found on a road in Utah, according to Monday's report from New York Daily News. The site mentioned that the car was still running and the airbag had been deployed. Michael, 30, was not found anywhere near the Honda Civic although his laptop and phone were still there.

It's unclear on where Michael was going although it seems likely he was the one who was driving. Apparently, the road where he was on would lead to the White Wash Sand Dunes, a large area of land.

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In a report from Deseret News, there was video surveillance from a convenience store in Monticello where Michael reportedly used his credit card.

Michael was last seen wearing black shoes, a green sweatshirt and jeans, said Grand County Sheriff Steven White.

"We're combining the area for anything we can find," White said. "We're deeming it suspicious, but there's nothing to indicate anything one way or another. The vehicle was just abandoned."

Michael's sister Kristin Cavallari earned her fame on reality television, including Laguna Beach and The Hills. She took to Instagram to post a photo of herself and her brother when they were younger and thanked everyone for all the support.