A pair of daredevils have risked their lives scaling one of Auckland's tallest buildings - and captured it all on video.

The men filmed themselves climbing the Pacifica building in downtown Auckland, which is the second tallest in Auckland at 178 metres.

Police have slammed their actions, saying they were putting their lives and the lives of others at risk.

Video of the stunt was posted to Instagram and shows the pair walking on top of the building and dangling from the scaffolding.

"I wish I could describe the complexity and process of becoming fearless," one of the men boldly stated in a caption attached to the video.

"Danger might be real but fear is a choice, all of the fears we don't face quickly become our limits," he added.

He teasingly warned users not to watch the video "if you have anxiety".

"Love you bro so don't you dare let go," wrote one person on Instagram, while another simply added: "Nope, nope, nope".

Police told Newshub that they had received no reports about the pair's antics but warned they risked being arrested, and worse.

"Anyone carrying out this activity is not only putting their own lives and others at risk but also risk getting arrested," they said.

Liz Scott, who heads the project for developer Hengyi Pacific, distanced herself from the antics and indicated it was the builder who should answer a media inquiry about how the men accessed the building.

She told the Herald to speak directly to Dan Ashby who is the construction chief for builder Icon on the site.

Ashby told the Herald: "The site team have appropriate security measures in place, including full time night security on-site and a lock-up procedure."

"We do not yet know how that was breached and are currently investigating to identify when and how it happened," he added.

The 57-level Pacifica apartments building are still under construction. Photo / Alex Robertson

He stressed that safety for his workers was paramount and that they would be implementing a stronger security presence after an internal investigation was completed.

The under-construction Pacifica recently reached its full height and is due to open later this year.

Anyone wanting the penthouse in the huge building might have to shell out $40 million, Liz Scott told the Herald in May.

The lucky owner would have access to priority elevator services so they could enjoy a degree of isolation, she said.