A stray "dog" found in the garden of an Australian east coast home is a rare purebred dingo, rather than an abandoned puppy as rescuers first thought.

The animal, named Wandi, was found in the back garden of a house in Wandiligong, 330km northeast of Melbourne.

He has been moved to a sanctuary for the endangered species after being identified.

"He is going to be a very valuable little thing, depending on his eventual development, and the way he continues to get along with everybody else in the sanctuary," said Lyn Watson, director of the Australian Dingo Foundation.

Ms Watson told the Australian Broadcasting Corporation that a DNA test had shown the animal to be an alpine dingo, vulnerable to extinction because of inbreeding, hunting and government eradication programmes.

The foundation plans to use the dingo puppy in its breeding programme, she added.

It was not immediately clear how the dingo ended up in the garden of the home, or where it came from.