Sea washes whale out of Sydney pool

A dead humpback whale, measuring about 12 meters (39 feet) long, lies in a rock pool at Newport on the northern beaches in Sydney, Australia. Photo / AP

The high tide has washed a dead humpback whale out of an ocean pool on a northern Sydney beach after it became lodged there.

The carcass of the young 10-metre male humpback was found lodged in the ocean pool at Newport Beach early on Wednesday.

Conservation officers had been hoping the high tide would move the huge mammal out of the pool.

On Wednesday night, an Office of Environment and Heritage spokeswoman said the whale had floated free of the pool in the evening.

"On the high tide it floated out of the pool," the spokeswoman told AAP.

"It was dark when it floated out, but I've been told that it's come out as we hoped."

She said the location of the carcass was now unclear.

"The tide was still rising at that point, so who knows," she said.

"It's a big ocean and a pretty dark night, so we've just got to hope that it goes into a spot that's going to be more accessible than today."

Once located, authorities plan to cut up the carcass and dispose of it at a tip.

National Parks and Wildlife Service said the whale most likely died three to five days ago, probably of natural causes such as a respiratory tract infection.

Pittwater Council said on Wednesday the beach would probably remain closed for two days.

It also warned of a possible increase in shark activity.