A baby whale which has been trying to suckle from a yacht in a Sydney bay is to be humanely destroyed.

The humpback whale, nicknamed "Colin" by Australian media, was found at the weekend attempting to suckle from a moored yacht at Pittwater Bay after being abandoned by its mother off Australia's east coast.

New South Wales state premier, Morris Iemma, said: "Our hearts are breaking with what's happening with baby Colin."

But a report by expert vets said blood tests revealed the two-tonne calf, believed to be only two to three weeks old, is in a poor condition and unlikely to live.

It was suffering from shark bite wounds and breathing difficulties.

Authorities expect to use a lethal dose of anaesthetic to put the whale down on Friday.

State Parks and Wildlife service spokesman, John Dengate, said: "They'll need to locate it first, and the poor little guy could have passed away already."

With time running out and rescue efforts becoming more desperate, an Aboriginal "whale whisperer" was brought to the bay during the afternoon to "talk" to the calf.

The "whisperer", Bunna Lawrie, said: "He heard me singing and came over. I looked at him and he was full of life. He had a few scratches and cuts on him and I was a bit worried about his eyes. All he needed is a mother's milk."

He pleaded with authorities for a change of heart on killing the calf.

Mr Lawrie said: "There was hope another whale could pick him up and adopt him. He could have at least learned to swim with them and eat krill and plankton."

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