A large slip that has swallowed about 50m of an Auckland car park has nearby residents worried, despite reassurances the land appearsto have stabilised overnight.

Part of the Rawene car park slipped away in the past few days after heavy rain in recent months.

Mokoia Ridge Apartments bodycorp chairwoman Claire Belfour said the slip was snaking towards residents.

"The car park was built on flimsy ground and this is just waiting to happen," she said.

Belfour said she had tried to report the cracks since they appeared last Friday, but did not get any response from either Auckland Transport or the Auckland Council earlier.

Nim Tucker, 26, a resident in one of the apartments, watched the slip happen on Sunday.

"There was a loud cracking noise, and then everything just fell in," Tucker said.

"It looked like a horror movie and something was sucking all the trees and car park from underneath, very scary."

Mokoia Ridge has 26 apartments, which were converted from a toy factory about 20 years ago.

A cafe operator, who wanted only to be known as Mrs Kim, said she was worried that if the collapse got closer to the shops, the telephone exchange could also go.

Auckland Council and Auckland Transport met concerned business owners and residents this morning.

Claire Belfour surveys a large slip that has taken out a car park behind the Birkenhead shops on Auckland's North Shore.

Geotechnical engineers were also at the car park this morning.

Auckland Transport said it was too early to say what caused the slip.

Birkenhead Town Centre Association chairman Pete Taylor said the disaster came at a busy time for the suburb, which is a major attraction for the Auckland Heritage Festival starting on Thursday.

"We are advising the public to enjoy the horse and cart rides and other entertainment in Birkenhead, perhaps a walk through LeRoys Bush and make the most of what Birkenhead has to offer, just perhaps catch a ferry over from the city or enjoy a bus ride over the harbour bridge into the Birkenhead Village."

Auckland Transport chief infrastructure officer Greg Edmonds said engineers had been monitoring the site for several months.

"We closed off more of the car park this morning and the road which runs behind it to ensure the area is safe.

"Our engineers are working with building inspectors from Auckland Council who are assessing all structures in the area."

Edmonds said the slip appeared to have stabilised overnight but access to much of the car park would continue to be restricted.

"The focus is on stabilising the site and then assessments can be done on what remediation work is needed."

Northcote MP Jonathan Coleman, whose electorate office is near the slip, said it would be impossible to say if the new developments in the area had contributed to it until Auckland Transport had investigated.

He promised to follow developments "very closely" and would keep business owners and residents updated.