For the first time in recorded history dolphins that usually stick to deep, offshore seas have been found stranded on a Victorian beach.

Key points: Southern right whale dolphins have never been recorded washing up in Victoria before

Southern right whale dolphins have never been recorded washing up in Victoria before Two of the dolphins have been found dead at a Port Fairy beach within weeks of each other

Two of the dolphins have been found dead at a Port Fairy beach within weeks of each other The species inhabits deep offshore waters and are rarely seen by people

Two separate southern right whale dolphins have been found dead at Port Fairy's East Beach in the state's south-west in the past couple of weeks, but only one was able to be retrieved by authorities for further examination.

Little has been known about the mysterious species of dolphin that inhabits cool waters across the Southern Hemisphere.

The natural environment programs officer at Victoria's Department of Environment, Land, Water and Planning, Mandy Watson, confirmed the dolphin that washed up in December was the first of its kind ever recorded in Victoria.

Southern right whale dolphins are very rarely sighted as they live off the continental shelf. ( Supplied: Flickr, wagon16 )

The second was found in a nearby spot last week which Ms Watson described as "very unusual".

"It is interesting that we have two [stranded] close together and in relatively similar locations," she said.

"These animals are normally found in deep water well offshore so they're very rarely seen in inshore waters."

Authorities examine 'really rare' specimen

The first dolphin that was found was picked up and is being examined by a team including scientists and traditional owners from the Eastern Maar Aboriginal Corporation.

The second very unusual dolphin washed back out to sea after being discovered and photographed by a member of the public.

Ms Watson said the department treated all strandings of whales and dolphins as emergency events, and urged people to ring a dedicated hotline if they came across such an incident.

"At times you'll have a really large specimen that needs to be dealt with or you might have a really rare specimen like this one," she said.

Southern right whale dolphins share a name with southern right whales, a species that also lacks a dorsal fin. ( Supplied: Andrew Halsall/WA Museum )

Southern right whale dolphins share their name with the southern right whales that nurse their young and migrate through coastal waters off southern Australia each winter.

"They're pretty easily identified by the black and white markings," Ms Watson said.

They don't have a dorsal fin, which is why they're called southern right whale dolphins.

"Because the southern right whales also don't have a dorsal fin."

Marine ecologist says little is known about the dolphins

Deakin University marine ecologist, Paul Tixier, said there were only about 30 records of southern right whale dolphins in Australian waters going back to the early 1900s.

That figure included both sightings and strandings, but most were observations made out at sea.

"They are very, very difficult to watch and and very hard to observe because they are very far out there," Dr Tixier said.

"They live literally off the edge of the continental shelf."

It has been believed the dolphin species live in groups of up to 1,000 individuals.

Dr Tixier said it was likely the two stranded dolphins were from a group that came unusually close to the south-west coast of Victoria, but the reason remained a mystery.

He said not a lot has been known about the species because, like other animals that inhabit deep offshore waters, studying them required a lot of resources and expensive equipment.

"We don't know much about these species, really, because they live in habitats that are so rough and so remote from us that it makes everything complicated," Dr Trixier said.

He said he was intrigued to find out if the examination of the carcass that was picked up would shed light on the animal's cause of death.