Video footage of a kayaker put in a sticky situation after a seal launched a large octopus at his face has gone viral across the world.

The unusual incident happened after a group of friends set out to capture images of seals off the east coast town of Kaikōura in the South Island.

The group were testing GoPro action cameras when they stumbled across the sight of a large fur seal in battle with an octopus at the ocean's surface about 10m away.

Kyle Mulinder was at the rear end of the double-hull kayak when the seal disappeared and suddenly reappeared beside the boat, throwing the octopus in his direction.

The video clip shows the stunned kayaker roaring after being slapped hard across the face by a tentacle as the octopus slips back into the water, lodging itself under the kayak's hull.

"I don't think the seal knew I was there," Mr Mulinder said.

"The crazy part was it was still alive, and then it grabbed on to the kayak... the video shows it's alive and it's not giving up," he said.

"It all happened so fast I don't thing I had time to be scared, to be stoked, to be surprised. Man, I got slapped in the face by an octopus."

He said he didn't think the seal knew he was there.

Afterwards a kayak guide took the octopus off the hull allowing it to disappear into the deep.

The seal had apparently tried to chew a tentacle before deciding the slimy morsel didn't suit its tastes.

"The octopus was huge... that was a creepy thing to happen," Mr Mullinder said.

It was certainly a moment the experienced kayaker would remember.

"Certainly you see cool things but not like this man," he said.

"You might see a seal fighting on octopus from distance, but for it to come up to you and for that to happen, that's a once-in-a-life-time.

"As much as it smelled like squid and was gross, it was pretty cool."

Since the footage went live on his @barekiwi and his friend, filmmaker Taiyo Masuda's Instagram account, he said he had received phone calls and emails requesting interviews from around the world.