UPDATE: A rep for the Kanawha County Sheriff's Office has confirmed that Shain Gandee's died due to carbon monoxide poisoning.
Police told TMZ that the deaths of Gandee, his uncle David Gandee and a third unidentified victim has been ruled an accident.
PREVIOUSLY: Carbon monoxide poisoning is being considered as a possible cause of death for "Buckwild" star Shain Gandee, his uncle David Gandee and a third unidentified person, who were found dead in Shain's truck on April 1.
TMZ reports that Shain's red Ford Bronco has been retrieved from the muddy pit where it was discovered and the bodies of all three victims have been recovered from the scene and have been transferred to the medical examiner's office, where autopsies will be performed.
Photos of the truck show that the vehicle was submerged in mud past the windows, which supports the theory that the victims likely died of carbon monoxide poisoning, after the exhaust fumes couldn't escape through the tailpipe due to the mud.
"It's not irresponsible of you to speculate that," Dan Humphries, spokesman for Kanawha County Sheriff's Office in West Virginia, told The Hollywood Reporter, acknowledging that carbon monoxide poisoning is a significant possibility. "But we're waiting on the coroner's report."
And while officials work to determine the cause of death, Shain Gandee's family is trying to find the funds necessary to give the 21-year-old a proper funeral.
His cousin, Ashley Gandee, told TMZ that she is organizing an off-road trucking event known as a "mud run" to raise money for the funeral. "I know the strain they are going through. It's hard to provide a proper burial. It's already tough with the loss of family members, expenses are tough as well," she told the website.
Shain Gandee was reported missing over the weekend, and was last seen at a local bar at 3 a.m. on Sunday morning, before his truck was found by a passing ATV rider on Monday.