Owha the leopard seal has returned to the waters of Auckland's Waitemata Harbour.

Photo: RNZ / Dan Cook

Over the past week, the curious seal has been stalking rowers at Waitematā Rowing Club on Te Atatu Peninsula.

She is also attracting big crowds of curious locals when she hauls herself up onto a pontoon to sunbathe.

Watch the full video report on the curious seal here:

Amy Robson - a member of the Auckland Rowing Performance Centre squad - said Owha had taken a keen interest in their early morning training sessions.

"The seal first showed its face a week ago when we were training, and has been back every session since," she said.

"The seal likes to stalk us as we leave the pontoon in the morning and it comes up super, super close and actually touched the nose of our boat yesterday."

Another rower, Sophie Egnot-Johnson, said while the close encounter with the seal was a bit scary, it was exciting to see one in the water.

Jordan McLarin often goes out for a paddle in his kayak and said he had been eyed up by the seal.

"The first time, I was just paddling along and [she] popped up next to me, gives you the old eyeball and has a look around and swims off again."

Mr McLarin said it was a bit of a worry seeing a large leopard seal up that close.

"It's about three metres long, so it's a bit unnerving, especially when you see the ripple in the water and it comes up and takes a look."

Tania Edmonds, who walks her dog in the area, said the seal had become a popular local attraction.

"There were hordes of people down here on Monday and they were just streaming down all day," Ms Edmonds said.

"There were a lot of photos on Facebook."

When Ms Edmonds saw the seal on Monday afternoon, it looked pretty happy, she said.

"She was sunning herself on the pontoon, just decked out over there on her tummy and she was very cute.

"When I left at about six, she was upside down with her fins up in the air."

When RNZ visited the area yesterday, Owha did not make an appearance until the rowers were off the water and the boats were back in the shed.

A shiny black head popped up next to the pontoon, and after a couple of attempts to haul herself up, Owha flopped up on the concrete.

National Institute of Water and Atmospheric Research (NIWA) marine mammal biologist Krista Hupman said Owha was no stranger to the Waitematā Harbour.

She was first seen in New Zealand waters in 2012, in Otago, and since then she had been a regular visitor around Auckland and Whangarei, Ms Hupman said.

Leopard seals hail from the Antarctic and are usually pretty solitary creatures.

But Owha was a bit different, Ms Hupman said.

One summer, Owha spent a lot of time around the busy Westhaven Marina in the central city.

"I think she's a bit of an exhibitionist actually, because she does like these public areas and she definitely is very curious," Ms Hupman said.

The seal had never displayed aggressive tendencies, but Ms Hupman said people should keep about 20m away.

If people come across Owha out on the water, the advice is do not panic and treat her with respect.