It's not known who is responsible for a blaze that ravaged Mt Eden's crater this week.
A firework is believed to have started the fire that spread more than 200 square metres across the crater in the early hours of Monday morning.
Twelve appliances attended and it was extinguished by 4am.
Avondale police Senior Sergeant Ross Endicott-Davies says a car was searched near the summit soon after police were called but there are no suspects.
Auckland city senior station officer Gary Lane says this is the second fire caused by fireworks at the summit this month.
In the earlier incident, a witnesses was able to put the flames out before firefighters arrived.
Open fires and fireworks are banned at all times in Auckland Council parks.
Council acting parks, sports and recreation manager Mace Ward says Monday's fire was a disappointing incident and is a reminder of the need for increased care during the dry summer season.
"Summertime presents us with dry conditions and increased fire risk, therefore we ask our visitors to take extra care on our parks and volcanic cones," Mr Ward says.
- Central Leader
Are our classrooms becoming overcrowded?