A woman in her 50s returning from Iran is New South Wales' sixth confirmed coronavirus case.
NSW Health has confirmed a woman that landed in Sydney last Sunday has tested positive for the deadly COVID-19 virus.
The woman flew back to Australia via Qatar, developing symptoms a day after landing.
Authorities have urged any traveller aboard Qatar Airways Flight QR 908 that landed in Sydney on February 23 to remain alert and self-isolate.
People who have been in contact with the woman are also being identified and monitored.
Earlier on Sunday a fifth person in NSW was confirmed as having the virus, a man in his 40s who also arrived in Sydney from Iran.
NSW chief heath officer Kerry Chant said the cases were not linked and they were not on the same flight, with the man arriving from Iran on a different day.
The male in his 40s arrived on February 22 and did not develop symptoms of COVID-19 until two days later.
He was tested on February 28 and was confirmed to have COVID-19 on Saturday, NSW Health said in a statement on Sunday.
The man has relatively minor symptoms and has been taken to Westmead Hospital.
The state's four previous cases have all been discharged from hospital.
Dr Chant said another man in his 50s was also under investigation for possible COVID-19 based on his preliminary lab results.
"Travellers from Iran should be particularly vigilant for symptoms as there has been a rapid increase in COVID-19 activity there in recent days," Dr Chant said in a statement.
Another woman who recently returned from Iran, a 63-year-old, is being treated at the Gold Coast University Hospital after being confirmed as having the disease.
The federal government on Saturday advised Australians against travelling to Iran.
Under the new restrictions, Australian citizens, permanent residents and their immediate family who've travelled to Iran will be required to self-isolate at home for 14 days from the day they left the country.
Foreign nationals who are in Iran will be banned from entering Australia for 14 days, from the time they have left or transited through.
