The province's Special Investigations Unit is investigating after a 54-year-old man from Armour Township died after his arrest by police.
On March 4, officers from the Almaguin Highlands OPP Detachment stopped a vehicle in Armour Township, near Burk's Falls.
As a result of police investigation, both the driver and passenger were arrested.
"While in custody at the Almaguin Highlands OPP Detachment, the passenger, a 54-year-old male from Armour Township, Ontario, went into medical distress and was brought to hospital," said Acting Sergeant Shona Camirand in a release. "On March 15, 2019, the male died at hospital."
The OPP has notified the province's Special Investigations Unit (SIU) which has invoked its mandate.
When police officers are involved in incidents where someone dies the SIU conducts an independent investigation to determine whether a criminal offence took place.