Raw video: Part of car park tumbles down bank as huge landslip forms on Auckland's North Shore

A large swathe of a car park that backs onto a busy suburban shopping precinct on Auckland's North Shore has collapsed in a landslip.

Part of the car park on Rawene Rd, Birkenhead, collapsed overnight, with earth continuing to slide down into Rawene Rd Reserve today.

Kaipatiki Local Board chair Danielle Grant said local politicians have been aware of a gradual widening of gaps in the car park for months.

"We could see there was absolutely movement there," she said.

"We certainly weren't expecting the slip to be that big. I think this has caught everyone by surprise."

Grant said Auckland Transport cordoned off parts of the car park a number of weeks ago.

But she said the local board had not been updated on any testing on the stability of the land in the intervening weeks, despite requesting it from Auckland Transport.

"It's a fast moving situation and quite unpredictable. Really now our concern is for everyone in the vicinity," she said.

"Our main message is please keep away because this is an unstable situation."

Images of the dramatic slip were posted on the Beach Haven and Birkdale Community Facebook page by local board member John Gillon.

"The slip is still active, so please be careful. A lamppost and fence are now at the bottom!" Mr Gillon commented alongside one of the photos.

A statement from Auckland Transport said an engineering geologist was at the site today to assess the slip danger and provide recommendations.

"Engineers are working to determine the stability of the fill and whether we need to cordon off further areas of the car park," said Auckland Transport.

"There is no immediate danger but members of the public must not enter the cordoned off area."

Danielle Grant said the car park will need to be replaced at some stage because it is "crucial to the economy" due to its proximity to the Birkenhead shops. 

Officials say that storm pipes will be redirected in the morning.