(ABC News) -- Carbon monoxide poisoning is suspected in the death of MTV reality series star Shain Gandee and two other men, whose bodies were found Monday inside a Ford Bronco submerged in deep mud.
Police are awaiting autopsy results before releasing a cause of death but confirmed that the muffler of the Bronco in which Gandee, 21, was found in the driver's seat was completely below the mud's surface. Gandee's uncle, David Gandee, and another man, identified Monday as 27-year-old Donald Robert Myers, were also found dead inside the SUV.
"There was no damage to the vehicle from an impact, it was just stuck in a mud hole," Cpl. B.D. Humphreys with the Kanawha County Sheriff's Office told ABCNews.com.
Gandee, of Sissonville, W. Va., and his uncle were last seen around 3 a.m. Sunday at Larry's Bar where they told friends they were leaving to go four-wheeling. Some 30 hours later, the county dispatch received a call of a disabled vehicle in a rural part of the county and used all-terrain vehicles to access the area, finding Gandee's Bronco upright but submerged in deep mud, according to Humphreys.
"I don't think that it's an unreasonable theory but we're going to wait and see what the medical examiner's autopsy reveals," he said of reports that the men likely died from carbon monoxide poisoning because of the muffler's position beneath the mud.
The area where the Bronco was found is one mile from Shain Gandee's residence in Sissonville, a rural part of West Virginia, according to officials. Police used a bulldozer to remove the Bronco from the mud.
MTV announced in February that "Buckwild," which followed the exploits of Gandee and his friends and family, would return for a second season. Early Tuesday morning the cable network confirmed it would suspend production of the reality series.
A spokesperson for MTV released a statement to ABCNews.com:
"We are shocked and saddened by the terrible news about Shain Gandee, and those involved in this tragic incident. We are waiting for more information, but at this time our main concern is for the Gandee family and their friends. Our thoughts and prayers are with them. Shain had a magnetic personality, with a passion for life that touched everyone he met and we will miss him dearly."
On the show's website, Shain Gandee was described as "the sociable and loyal High School Prom King who loves four-wheeling, but loves his parents most of all."
The show first premiered on MTV in January amid criitcism that it depicted negative stereotypes of West Virginians. Sen. Joe Manchin wrote a letter to the president of MTV before the show aired criticizing it for encouraging youth to misbehave for the camera.
"You preyed on young people, coaxed them into displaying shameful behavior – and now you are profiting from it. That is just wrong," wrote Manchin.
Some television critics even called the show the "Redneck Jersey Shore," which debuted in the same time slot that show once held on MTV.
Shain Gandee's costars took to Twitter to express their grief in the hours after his death.
"I just don't understand," tweeted Shae Bradley. "Just woke up and it's not all just a night mare."
"Rip Shain Gandee. You are an angel, I know you will watch over me," wrote Ashley Whitt.
ABC News' Josh Haskell contributed to this report. Click here for more from ABC News.