Officers responded to a 911 call early Dec. 15 and arrested the woman, transporting her to jail in a police wagon.
Const. Brian Montague says in a news release Tuesday evening that the woman was not responsive when the vehicle arrived at the jail.
He says paramedics were called and she was taken to hospital.
Montague says the woman died in hospital on Tuesday but the cause of death is not yet known.
He says the Independent Investigations Office, which is the province's police watchdog, and the coroners service are looking into the death.