A Schoolcraft County Jail inmate was found dead in his bed on Saturday morning, according to the Schoolcraft County Sheriff's Department.
The Manistique Public Safety Department is conducting an independent investigation of the death.
"We have to have an outside agency conduct an investigation to relieve the situation of any possible appearances of impropriety," said Schoolcraft County Sheriff Grant Harris.
The sheriff's department is conducting an investigation of the incident as well.
"At this point of time in our investigation, it appears that this death is of natural causes," Harris said. "However, in the interest of justice, our office will be thoroughly investigating this incident in the days and weeks to come."