A 26-year-old man died at Darwin correctional centre on Saturday, Northern Territory police said.

It was the territory’s second reported death in custody in just a matter of days.

The man was found unresponsive in his cell by correctional officers at around 7:50am on Saturday.

“Medical assistance was provided but the man was declared deceased at the scene. The death is not believed to be suspicious,” NT police said in a statement. A report will be prepared for the coroner.

On Tuesday evening, a 25-year-old man died in police custody in Darwin’s northern suburbs, after police arrested him following reports of an assault at a retirement village in Casuarina.

They detained him in the rear cage of a police vehicle.

Police said that a short time later the man had laboured breathing. St John Ambulance was contacted while police began CPR. The formal cause of death has not been determined.

“St John Ambulance members attended and conveyed the man to Royal Darwin Hospital where he was later declared deceased at 10:10pm,” a police statement about the Tuesday death said.

“A crime scene was established at the police vehicle and the location of arrest.“

The NT major crime unit was investigating the death, with oversight from the Professional Standards Command. Police were also investigating the death on behalf of the coroner.