A stranded humpback whale near Dargaville has been killed, the Department of Conservation (DOC) says.
The female whale, which was found with a now dead calf, has been stuck on Ripiro Beach since early Sunday.
More than 100 rescuers have tried to refloat the whales since then.
DOC said it made the decision with local iwi and Project Jonah because the whale's condition was deteriorating.
Nearly 50 people were there to farewell the animal, singing waiata, and the local iwi Te Roroa said a karakia.
Kirsten Crichton, who lives in Dargaville, said the decision to euthanise the whale was tragic but she supported it.
She said the fight to live seemed to have left the mammal.
"I was here on Sunday as well and ... she was quite a bit further up the beach," she said.
"You've seen the strength and determination of how far she's got to here and now you can just see the change, you can see she's weak and tired - it's heartbreaking to see really."
Whale specialist Ingrid Visser said a number of solutions were explored before the decision was made to put down the whale.
"There were some thoughts that we could get a digger in there and help push her but the problem is that they've got very long pectoral fins and if you try and push them you could dislocate the shoulder as well," Dr Visser said.
Alan Nesbit, the spokeperson for the local iwi Te Roroa, said euthanising the whale was a huge job and but it had to be done.
He said an autopsy of the mammal was vital for iwi.
Earlier today, Kaipara Mayor Jason Smith told Morning Report the prospects of refloating the whale were not looking good.
"There's a bit of sea fog and the sun hasn't yet risen but things are looking grim actually. The whale has been on the beach for more than 48 hours and so the prospects are not good," Mr Smith said.