A "mysterious string of lights" spotted in the sky above Auckland on Sunday morning has been confirmed as Elon Musk's SpaceX Starlink satellites.

Simon Russell was half-awake and letting in his cats around 5am when he noticed some strange lights in the eastern sky.

He described seeing "40 or 50 lights in a continual trail trickling over the horizon" just above the rooftop of his Albany neighbour's rooftop for a number of minutes.

"It was 5am, I was half-awake and I was thinking, what am I looking at? It was quite freaky," Russell told the Herald.

"It just looked too uniform to be something alien ... it looked like a satellite formation but then I've never heard of a string of 40 or 50 satellites all in a row."

He woke up his wife and son because he "needed witnesses, otherwise they would never have believed me".

Leaning on the fence, he used his cell phone to capture an image of the light show.

SpaceX Starlink has launched several chains of up to 60 satellites in recent years, as part of a plan to create a constellation of broadband satellites for worldwide high-speed internet services.

They have been spotted with the naked eye travelling over New Zealand previously. The most recent sighting was in March.

The findstarlink.com website confirms the satellites passed over Auckland early Sunday morning.

The last sighting was at 6.07am, for a duration of four minutes, looking southwest (241 degrees) to northeast (36 degrees).

It comes as Rocket Lab's launch of satellites from its facility on Māhia Peninsula failed last night.

Following a successful lift-off, first-stage burn, and stage separation, Rocket Lab experienced an anomaly during its 20th Electron mission, "Running Out Of Toes".

"The issue occurred following second-stage ignition during the flight on May 15, 2021 UTC, resulting in the loss of the mission," the company said in a statement.

"The launch vehicle's second stage remained within the predicted launch corridor and caused no harm to the public, Rocket Lab's launch or recovery crews, or the launch site.

"Electron's first stage safely completed a successful splashdown under parachute and Rocket Lab's recovery team is working to retrieve the stage from the ocean as planned."

The rocket was carrying two Earth-observation satellites for BlackSky, an Earth-imaging company with civilian, intelligence community and defence customers.