Sunday morning shoppers in the New Zealand city of Auckland caught glimpses of the unexpected when a store's promotional screen played pornography for several hours.

The NZ Herald reported that sportswear retailer Asics stunned pedestrians as hackers played a pornographic video from the early morning until staff at the store turned it off at around 10 am.

A spokesman for Asics confirmed to Reuters that the screen above the store's entrance was hacked and apologised to those who saw the explicit content.

"Our Shortland Street store was subject to a cyber security breach," the spokesman told Reuters by email on Sunday.

"We are investigating the situation and working to mitigate it happening again in the future."

One witness, Tanya Lee, told the NZ Herald that she was on the way to breakfast with her 7-year-old son when she noticed the video.

"I took a second look because I just ouldn't believe what I was seeing," Lee said.

"It's totally inappropriate and offensive, not something that you want kids exposed to, and it's also embarrassing for Auckland as a tourist destination."

Police told Reuters that no report had been lodged in relation to the hacking.

- Reuters