Structural engineers and a surveyor from the Auckland Council were inspecting the Palace Hotel, formerly known as the Aurora Tavern, after a member of the public noticed metre-long cracks about 4pm. It is understood the building has shifted 80mm.
Wellington sex industry leaders John and Michael Chow recently bought the landmark building opposite the Sky Tower for $3.3 million to restore it and convert it into a brothel.
The original building, built in 1886, appeared to be sound but the cracks were in two annexes, added in 1889 and 1912.
A decision would be made soon about whether to demolish them, said Auckland Council spokesman Glynn Walters.
"While it's a tragedy to lose parts of a listed building, health and safety of people around it come first."
"We're still assessing the damage. I can't say whether it will come down."
Auckland Council member Sandra Coney, also a heritage campaigner, was waiting on engineering reports.
"Everyone is pulling out all the stops to see if it's salvageable."
Musician Andy Hodgins was meant to play at the neighbouring Fiddler bar last night.
"We were sitting on the balcony having a beer and we felt this vibration like a big truck going past," he said.
"We were evacuated really quickly. The police just told us to get out. I think it's God striking down a house of ill repute," he joked.
Cherry Reynolds, of the New Zealand Historic Places Trust, said the Palace Hotel was one of the "rare" corner pubs left in Auckland.
"I'm absolutely gutted that it's coming down."
Police cordoned off Victoria St West between Hobson and Albert, and neighbouring buildings were evacuated.
Inspector Chris Robinson said the hotel "could collapse at any time".
Several hundred people gathered to watch the drama unfold and could hear the building move.
The building is a category B listed building.
- The New Zealand Herald