Incredible footage of orcas swimming in Mangawhai Estuary

A spectacular video has been taken showing orcas swimming in the Mangawhai Estuary, Northland on Tuesday.

The footage was taken on New Year's Eve, showing two large orcas rising to the surface to breathe.

Witness Daniel Mackinnon told Newshub they came "pretty close" to shore.

"We look out and there are two orcas swimming past us," he said.

"They kind of just swam into the estuary, and then 20 minutes later swam back out to sea."

Mackinnon says the orcas drew a lot of attention.

"About 20 people got their phones out and were watching them," he says.

The sighting comes just days after an injured orca whale was successfully freed from a crayfish line he became tangled in near Tutukana, also in Northland.

Marine biologist Dr Ingrid Visser says she's optimistic about that orca's future now the line is gone.

"It's cut very deeply into him, it's going to take a long time to heal, but we've got high hopes that it will heal completely," she told Newshub.

"The last we saw of him, he was out in the middle of the Firth of Thames and his family was about 10km away.

"But they should be able to hear him, he's calling out, and now he's free he can catch up to them."