Australian health authorities have informed the World Health Organisation they had detected the country's fourth probable case of Severe Acute Respiratory Syndrome (SARS).
Chief medical officer Richard Smallwood said the case was a45-year-old woman from Queensland state who had been under investigation since April 10, when she returned to Australia from southern China.
Smallwood said the woman had fully recovered from her illness and had not infected her family or anyone who came into contact with her.
He said two other people remained under observation after displaying SARS-like symptoms, a 57-year-old woman in Western Australia and a nine-year-old boy in New South Wales.
Australia reported its first SARS cases on April 17, when three siblings visiting from Canada were found to have had the virus and fully recovered.
A British tourist sparked a SARS false alarm in Australia last month but turned out to have a severe case of influenza.
Smallwood said 187 people had been assessed and cleared of the virus since tightened quarantine measures were introduced on April 4.
New South Wales, Australia's most populous state, on Wednesday said SARS was being added to a list of dangerous diseases such as typhoid and tuberculosis, meaning suspected sufferers face six months jail if they refuse to take tests or go into quarantine.
"The measures available may seem tough, but they are in place to safeguard the health of our community," NSW Premier Bob Carr said.
"We've got to protect ourselves, it's as simple as that, we're entitled as a community to protect ourselves from what is emerging as a very serious outbreak of an infectious disease in our region."
SARS has killed more than 230 people and infected more than 4,200 worldwide.
AFP