A pair of divers swimming off the north coast of New Zealand couldn’t believe their luck when they came across a bizarre-looking giant worm measuring more than 8m long during a recent dive.

At first they weren’t quite sure what to make of it but they made sure to whip out the camera and record the strange sea creature as it moved through the water. The amazing video shows the hollow animal, which resembles a wind sock crossed with a pink pickle, slowly floating along at a depth of about 10m.

The footage was captured by Steve Hathaway, 56, and Andrew Buttle, 48, who were diving in the waters off the coast of Whakaari, an active stratovolcano on an island in New Zealand’s far north on October 25.

According to The Sun, the pair initially set out on the dive to record footage for the island which Mr Buttle inherited from his grandfather, when their focus was stolen by the unusual beast.

The hollow wormlike creature is made up of hundreds of thousands of organisms and is known as a pyrosome.

In the video, it can be seen moving delicately through the water, occasionally shuddering and pulsating while the divers swim gently around it, trying not to disturb it.

“Having never seen one in person or even footage or photos of one before, I was quite incredulous and elated that such a creature existed,” Mr Buttle said. “It was very puzzling but also fantastic to be able to view it right up close and spend so much time with it.”

He believes the animal was a pyrosome, which is made up of hundreds to thousands of individual organisms, known as zooids.

“I believe it is possibly a pyrosome — occasionally they are caught in nets but not many intact large specimens have been caught to my knowledge,” he said.

The fairly remote waters off the coast of Whakaari likely provided the ideal conditions for the animal to grow so large.

“The island is 48km from the mainland, and there is a vast amount of fish life and nutrients in the water that may have had the right circumstances to become so large,” Mr Buttle said.

“At times there can be blooms of thousands of small versions of these creatures in many parts of the world, but not something I had ever seen before.”

Steve Hathaway, who founded Young Ocean Explorers, an educational entertainment platform encouraging children to explore the world’s oceans, said: “Without a doubt the highlight of the trip was to find the pyrosome — I’ve wanted to see one for many years now.

— with The Sun