The fire, which caused the Gulf Harbour Country Club clubhouse to collapse on itself, was being treated as suspicious.
Fire and Emergency NZ were called to the scene just before midnight on Tuesday.
At its peak, 17 fire trucks were at the scene and more than 50 personnel.
The building was now a "complete write-off" and crews still had about six hours worth of work ahead of them to fully extinguish the fire.
The blaze was being treated at suspicious and there were "similarities" with Saturday's fire.
That included "things that aren't adding up that could make the cause suspicious".
FENZ group manager Phil Larcombe told Morning Report the fire took a lot of trucks away from responding to weather-related callouts overnight.
"Crews are still there, just monitoring. Obviously as we do, we don't walk away until we're confident that everything is out. And obviously keeping a secure presence on the scene to make sure that the scene is preserved for our fire investigators also."
Seven fire trucks remain at the scene at firefighters work to fully extinguish the fire.
Police said they were called to assist at 11.52pm.
Police said a scene guard would remain in place until a fire investigator could attend the scene.
"Anyone with footage or information that may assist is asked to contact police via our 105 phone service, referencing job number P058799465.
Gulf Harbour resident Lucille de Abreau said it was "heartwrenching" to see the country club go up in flames.
De Abreau described the club house as the "heart of the community".
Her and partner, Ryan van Beurden, were dealing with flooding through their ceiling late last night when they smelled smoke and called the fire brigade, thinking it was their own property.
Van Beurden, who lives 200 metres away from the abandoned golf-course club house, said he went to the site at midnight, and saw the fire consume the building, starting at the site of a former café, spreading through the main buildings and office, and up to the second floor - when it collapsed.
Van Beurden and de Abreau were both former members of the club, and said they were nott surprised it went up in flames, following the fire at the golf shop on Saturday.
De Abreau said plenty of former members and friends have listed and sold up to move elsewhere.
"The Country Club was an amazing course and it's truly a devastation to the community."
Environment group Keep Whangaparāoa's Green Spaces (KWGS) said it was devastated by a second fire.
In a statement, it said KWGS executives had received messages and calls from "distressed members, locals and concerned individuals from around New Zealand and overseas since the fire was first reported".
"The community has been calling on authorities and the owner to secure the clubhouse buildings since the golf club abruptly closed in July 2023. Since then the clubhouse has been subject to extensive graffiti and vandalism. KWGS supporters have been disappointed that no attempt has been made to fence the clubhouse site off and make it safe and secure."
But KWGS said it still believed the golf course was a viable business with a vital role in the community.
"KWGS have always maintained a new golf course owner would most likely demolish the existing clubhouse building which needed extensive remedial work and construct a more appropriate fit-for-purpose clubhouse.
"KWGS continues to lobby both Auckland Council and government to ensure no resource consent for housing is granted on the GHCC land."
It is the second time within a week that the country club has caught fire.
A golf shop was found on fire before 3am on Saturday, 18 May.
Local resident Greg Taylor, whose home was about 400 metres from the scene of the fire, said he woke to see the blaze from his bedroom window.
"It just kept getting bigger and bigger and bigger," he said.
He said he was not too surprised given the buildings had been empty since the middle of last year.
He feared the main country club building would be next.
"The building itself is completely abandoned, just about every window's been smashed."
Residents had reported it to police and the council, he said.
The club, a former training ground of world champion Lydia Ko, was abruptly closed last July.
Plans to redevelop the golf course and country club have been off and on, and an application was made to put its owners into liquidation in April.
