Kristin Cavallari's brother, Michael Cavallari, appears to have gone missing in Utah. The 30-year-old disappeared over a week under suspicious circumstances.

On Nov. 27, the Grand County Sheriff's Office received a report that there was an abandoned Honda Civic along Interstate 70. Authorities identified Michael as the driver after finding credit card receipts in the car, which led them to a convenience store in Monticello, Utah. The convenience store had security footage of Michael, confirming he was the one driving the vehicle.

The Deseret News reported that Cavallari's laptop and cellphone were found in the empty car, which seemed to have hit a large rock on the side of the road. The car's engine was running and the airbag was deployed.

Grand County Sheriff Steven White told FOX411, "Right now everything is pretty status quo. We are conducting follow ups, and there is not much more to add to that. We are still out talking to people trying to piece things together."

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

Kristin and her family have remained silent about the disappearance until earlier today. The former reality star, who just gave birth to a daughter, has tweeted to thank people for their support during this trying time.