NT Police are investigating the non-suspicious death of a 45-year-old Tiwi Islands woman in Darwin last night.

Shortly before 9:00pm the woman was taken into protective custody due to her highly intoxicated state, and transported to the sober-up shelter.

Police re-attended at 10.21pm when it was observed the female was not breathing. Police provided first aid and attempted CPR, which was unsuccessful. St John Ambulance attended and the woman was pronounced dead just before 11:00pm.

The investigation is being managed by Crime Command and a file is being prepared for the Coroner.