The prisoner, whose name is being withheld for cultural reasons, was from the Mornington Island community in the Gulf of Carpentaria, confirmed Mornington Shire Council CEO Frank Mills.
"The details are very scant here in the community," Mr Mills told NITV News.
"We're not able to get a lot of information at this point in time."
The death occurred a day before 22-year-old Tane Chatfield was found dead in his cell at the Tamworth Correctional Centre on September 20.
The 48-year-old inmate was found unconscious just before 11am at Townsville Correctional Centre on September 19, a Queensland Corrective Services spokesman said.
Attempts to resuscitate him failed and medical staff declared him dead, the spokesman said.
Homicide detectives from Brisbane are investigating and a 41-year-old man "is currently assisting with inquiries", police said in a statement.
“There’s been an altercation between two prisoners, but there’s a bit of a separation (after the fight) before the deceased collapses,” Corrective Services Investigation Unit (CSIU) Acting detective Inspector Rosemary Walker told the Townsville Bulletin last week.
“We can’t really speculate on what’s caused his death, but preceding his death there has been an altercation, but we are going to be relying on an autopsy and witness statements.
“We don’t know about his pre-existing health conditions or anything like that, so all of that will be examined.”
A Coroners Court of Queensland spokesperson told NITV News the autopsy had been carried out in Townsville, but the cause of death was not yet determined.
"[The inmate's] family will be advised of the results of the autopsy as soon as they are available," the spokesperson said in a statement.
Any death in custody is reported to the State Coroner for a mandatory inquest.
As such, the State Coroner will oversee the investigation of the circumstances surrounding the death of the prisoner. A date for the inquest will be determined after the police investigation is complete.