A RARE video captured the brutal moment a pack of 60 killer whales hunted down and devoured the world’s biggest animal in a feeding frenzy.

Tourists off Australia’s Bremer Bay watched as the orcas surrounded a 60ft endangered pygmy blue whale and tore it to shreds in a savage 90-minute attack.

The event is so rare it’s only the fourth time ever caught on film.

Shocking footage showed dozens of black-and-white fins slicing through the ocean as the distressed whale fought for its life.

In the chaos, up to 30 orcas at a time engulfed the doomed leviathan, which rolled helplessly in the water with bite marks already covering its body and an oil slick trailing from its wounds.

Marine biologist Jennah Tucker watched the savage event unfold from aboard a tour vessel operated by Naturaliste Charters.

She confirmed that five different orca families joined forces to take down the giant.

Tucker told Australian outlet ABC: “We estimated about 60 orca involved, likely more than that.

“We’ve confirmed five different family groups were involved.

“Quite often, many will move in once it’s over.

“But in this case, we saw 20 to 30 animals at a time crowding around the whale to take it down.”

The beasts stalked the blue whale for 90 brutal minutes in Bremer Canyon – a renowned marine hotspot – before it was overwhelmed.

The aftermath was carnage, with the sea stained red and the whale stripped to the bone.

“It was all over pretty quickly for such a big animal,” said Tucker.

“We’re all still pretty shell shocked.”

As the orcas feasted, many of them breached and tail-slapped the water in what witnesses described as a grisly celebration of their kill.

Photographer Machu Yoshida, who was also on board, called the moment “bittersweet.”

“I felt mixed emotions,” she told Yahoo News.

“I love blue whales so it was sad to watch its life being taken by the orcas, but they were all so intelligent, it was incredible to watch them do it.”

The slaughter served as both a deadly lesson and dinner for the pod’s youngest members, including a one-month-old calf still lacking teeth.

Tucker said: “They are involved from a young age — this calf has no teeth but stuck by mum’s side.”

In a Facebook post, Naturaliste Charters wrote:  “We witnessed an incredible and rare event yesterday as multiple pods of orcas successfully hunted a blue whale in Bremer Canyon… As the blue whale’s fate was sealed, orcas celebrated with breaches and tail slaps.”

Researchers hope the footage will shed new light on orca behaviour, particularly in group hunting tactics – but admitted the predators remain notoriously difficult to track.

Despite multiple tagging attempts, orcas often outsmart scientists by removing tracking devices.

Robert Pitman, a cetacean ecologist at Oregon State University, called it “the biggest predation event on the planet.”

He added: “We haven’t seen things like this since dinosaurs were here, and probably not even then.”

It comes as orcas declared war on the world’s biggest sharks as they train themselves in new deadly skills to kill the sea beasts.

And the “world’s loneliest orca” trapped in a tiny pool for 32 years is experiencing the “worst form of torture”, experts claimed.