US expert Marco Restani said it could take years to find a solution, calling the disease "the most significant wildlife disease I have seen".

Devil Facial Tumour Disease first manifests itself as small lesions and lumps around the animal's mouth, then as cancerous tumours on the face and eventually throughout the entire body. Death occurs within months, often from starvation.

"The population decreases that we see -- 80-90 percent in some areas -- are huge," said Restani, of St Cloud University in Minnesota. "These decreases that we see in the top-level predator in some areas raise the alarm that perhaps not all is well in the ecosystem.

"I think people should take it bloody seriously."

The feisty animals, made internationally famous by the cartoon character "Taz", are the world's largest marsupial predator since the extinction of the thylacine, or Tasmanian tiger, which was largely wiped out by hunting.

Like the thylacine, it was once found all over Australia. Isolated Tasmania became both animals' final refuge after the introduction of the dingo by Aboriginal peoples.

Restani, who recently completed a survey of the devil population, was speaking during a meeting in Tasmania's second city about the problem. He said if the disease turned out to be a retrovirus as expected, it could make it hard to find a cure.

"If this is indeed a retrovirus, it actually takes years and years of effort both in terms of staffing and resources to determine what to do about it," he said.

The disease has already spread through eastern parts of Tasmania, with reports of cases in other areas as well.

TERRA.WIRE