A pygmy whale calf has died almost a day after it became beached in north-east Tasmania, marine biologists say.

Experts at the site in Boobyalla in the north-eastern tip of Tasmania refloated and stabilised the whale in shallow water and were hoping to release it once it regained some strength.

The whale was discovered washed onto the beach at Boobyalla near Musselroe Bay about 1:00pm Saturday.

The whale was found beached near Musselroe Bay on Saturday afternoon. ( Supplied )

Police and volunteers attempted to refloat the whale on Saturday afternoon but was eventually washed up again and died despite the efforts of wildlife experts.

Wildlife Biologist Rachel Alderman said the whale appeared to be about one year old.

"It's a relatively young one, she might be only relatively recently weened from her mother and maybe immaturity is a factor," she said.

"She's at least a year old based on her length so we don't think she was a dependent calf."

Ms Alderman said not much was known about the species.

"Most of what we do know about them is from stranding events," she said.

"We might get a couple a year all around Tasmania.

"We've had a couple in the last few months so it's an interesting season for these guys."

Death likely related to illness

Wildlife biologist Kris Carlyon said while a cause of death was yet to be determined, it was likely related to an underlying illness.

"We'll take that [the body] back to Hobart, we will do a full necropsy," Mr Carlyton said.

"We will try and find out why it might've died, what sort of underlying disease or illness it might be carrying."

He said the carcass would provide valuable samples, which should shed more light on the species, which is rarely found alive in Tasmania.

"This is one of the best specimens ... for this species that we've seen," he said.

"We'll collect a bunch of samples for our archive and for ongoing research and we'll offer up the skeleton and whatever tissue the museum [Tasmanian Museum and Art Gallery] might want as well.

"There's a lot of information we'll gather from this animal."

Wildlife Ranger Matthew Jones was involved in the attempted rescue, which he described as "involved".

"Because the whale has been stationary for so long, we try and get them back into the water to get them used to being in the water," he said.

"It also cools them down ... but also allows them to get their muscles moving again so when they are ready to be released ... off they go.

"When they do get released it's a really great feeling."