Rugged terrain, strong winds and darkness hampered the efforts of firefighters who battled the 13-hectare blaze on Browns Island this week.
Mysterious circumstances still surround the blaze, that has charred nearly half of the nature reserve and taken more than two days to extinguish. When authorities went to investigate smoke billowing from the island on Thursday, they found a woman who told them she had been stranded on the island since Monday and lit the fires to raise the alarm.
The woman was treated at Auckland Hospital for dehydration, but was resting at home on Friday. Police have not released any more details around how she got to the island, because she told her rescuers she did not know.
Browns Island, also called Motukorea, is a 5.5km kayak from St Heliers, and about 1.3km from Little Bucklands Beach.
Fire investigators said there was no evidence of a boat or kayak near the fire scarred areas, and they did not believe the woman would have been able to swim there.