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Off the coast of Australia, Killer whales are well and truly living up to their vicious name.

Not content with preying on fish, seals and sea lions, orcas have been spotted attacking and killing Humpback whales, as well as Spinner dolphins.

Researchers witnessed at least 22 individual attacks on Humpback groups near Carnarvon - and on at least 14 occasions the prey was killed and left to mercy of opportunistic sharks.

Not content with preying on fish, seals and sea lions, orcas (pictured) have been spotted attacking and killing Humpback whales and Spinner dolphins. Researchers witnessed at least 22 individual attacks on Humpback groups - and on at least 14 occasions the prey was killed and left to mercy of nearby opportunistic sharks

The observations were carried out by Robert Pitman and his colleagues from the National Oceanic and Atmospheric Administration (NOAA).

They identified 19 Killer whales from three groups attacking Humpback calves, and in total, they witnessed 22 individual attacks on the Humpback groups.

They additionally used satellite tagging to follow an adult female up and down the western coast of Australia near Shark Bay. 

During a six-day period, the female and her group attacked eight Humpback calves, and at least three of these calves were killed.

The team also spotted the Killer whales preying on Spinner dolphins, and during one particularly violent attack, the whales managed to kill two of the dolphins.

The whales' success was attributed to the fact they hunt in groups.

Following a number of attacks on the calves, the bodies were torn apart by Great White and Tiger sharks in the area.

'These events are so infrequently observed that documentation of even individual attacks continue to appear in the scientific literature,' said Mr Pitman in Marine Mammal Science.

'The prevalence of presumed killer whale tooth rake marks on the flukes and flippers of nearly every large whale species has been cited as evidence that attacks might, in fact, be fairly common.'

During the attacks, Mr Pitman and his team also spotted a number of defensive techniques adopted by the Humpback whales.

They used coral reefs as a form of shelter and protection, and the mothers were also seen pushing their calves into shallower water.

Mothers were also spotted lifting the calves out of the water and throwing them onto their backs to keep them out of harm's way.

During the attacks, Mr Pitman and his team also spotted a number of defensive techniques adopted by the Humpback whales. They used coral reefs as a form of shelter and protection, and the mothers were also seen lifting calves out of the water and throwing them onto their backs to keep them out of harm's way (pictured)

The observations (pictured) were carried out by Robert Pitman and his colleagues from the National Oceanic and Atmospheric Administration (NOAA). The team also spotted the Killer whales preying on Spinner dolphins, and during one particularly violent attack, the whales managed to kill two of the dolphins

While others fought back using their tails, or travelled with 'escorts' - males that accompany the mother and calf through the water.

'Humpback "escorts" vigorously assisted mothers in protecting their calves from attacking killer whales, and a white shark,' said the team.

'This expands the purported role of escorts in humpback whale social interactions, although it is not clear how this behaviour is adaptive for the escorts.'

Overall, the findings support the notion that Killer whales routinely hunt and eat other whale species.

Other Humpback whales fought back using their tails, or travelled with 'escorts' - males that accompany the mother and calf through the water (pictured). 'Humpback "escorts" vigorously assisted mothers in protecting their calves from attacking killer whales, and a white shark,' said the team

The researchers additionally used satellite tagging to follow an adult female up and down the western coast of Australia (pictured). During a six-day period, the female and her group attacked eight Humpback calves, and at least three of these calves were killed

'Reports of killer whales preying on large whales have been relatively rare, and the ecological significance of these attacks is controversial,' continued the researchers.

'We report on numerous observations of killer whales preying on neonate humpback whales based on reports we compiled and our own observations.

'Overall, our observations suggest that humpback calves are a predictable, plentiful, and readily taken prey source for killer whales and scavenging sharks for at least 5 months a year.