Fire crews keep blazes clear of billionaire Graeme Hart's Auckland estate

Firefighters tackled two blazes near the clifftop estate of billionaire Graeme Hart in Glendowie, Auckland, on Friday.

Fire and Emergency was alerted to the first blaze, above Gentleman's Bay Beach, at 3.18pm on Friday by a person on a vessel, shift manager Josh Pennefather said.

Three fire crews and a helicopter using a monsoon bucket fought the vegetation fire, which covered an area 100 metres by 50 metres, he said.

The fire was extinguished by 7.40pm, then a 111 call alerted FENZ to a second fire about 10.50pm, Pennefather said.

Four fire crews went to the second fire, just east of the first, which they accessed from Waitara Road, he said.

With the helicopter not able to operate overnight, firefighters attacked the blaze from the ground and it was out by 1.40am Saturday, he said.

Crews stayed on site overnight to monitor for flare-ups before leaving the scene around 6am.

A fire investigator was looking into its cause, Pennefather said.

Police said they assisted with an emergency response to a scrub fire and enquiries into the fires are continuing.