A desperate race is on to save a deteriorating baby orca that has become separated from its pod and its mother.

It's in Bay of Plenty, but Newstalk ZB has agreed to keep its exact location secret to protect it from onlookers.

The station has been tracking the whale's progress behind the scenes to help with that protection.

But the Department of Conservation has now gone public with some details.

The orca was first seen earlier this month and it could be anywhere between six months and a year old.

No-one knows for sure, but what is known is that it's going hungry, it's getting dehydrated - and its situation is "dire".

Orca researcher Ingrid Visser is with the orca, after arriving at the weekend.

She hasn't dealt with a case like it in 30 years.

"It's using all of its energy to survive at the moment and we don't want it to have to spend its energy to avoid boats and people who just want to take selfies with it.

"Our hope is it's family will come back," she said.

But nobody knows what the baby orca's family is, and people are being asked to keep a look out.

It is such a rare event that Mr Visser is flying in another expert from overseas, who's due to arrive tomorrow.

"We'll be able to get a much more accurate assessment from the world expert," she said.

But Dr Visser said there was no question of there being a race against time.

"It will depend on the water temperature, it will depend on the currents, it will depend on all sorts of things.

"If we can intervene and get some fluids into it then it can survive for at least a couple of months," she said.

But the Department of Conservation has put a no intervention policy in place, meaning Dr Visser is limited in the help she can give.

"We are going to wait until the expert from overseas comes in and assesses the calf and then at that point we will be advising DOC on what we think the situation warrants and how it should be handled.

"We'll take it from there," she said.

Some locals have affectionately named the baby orca Bob, because of the way it has been helplessly bobbing up and down.