Three cases of coronavirus have been confirmed in New South Wales with links to Wuhan, the Chinese city at the centre of the deadly viral infection.
The three infected men, aged 35, 43 and 53, have been isolated in hospital to prevent the virus spreading further.
NSW Health Minister Brad Hazzard said two of the men had travelled to Sydney directly from Wuhan, while the third had travelled from the southern city of Shenzhen.
"Each of these gentlemen had some connection with Wuhan," he told reporters on Saturday night.
"Please be aware that we do now have coronavirus here in Sydney. If you've got symptoms, ask yourself whether you've come in recent weeks from China, particularly from Wuhan."
Mr Hazzard said the state's health department had done everything possible to identify and contain the virus.
"Public health authorities have taken all the major steps, and these cases are now in isolation in one of our major hospitals and are getting world class treatment," he said.
The three infected patients deserved to be thanked for coming forward, Mr Hazzard said.
"I'd like to thank each of these three people because they have been exemplary in the way that they presented themselves," he said.
"We are taking a very precautionary approach and making sure they are in an environment where we can keep them under close observation."
NSW chief health officer Kerry Chant said that with Sydney's close connections to China, it was inevitable the virus would eventually reach NSW.
"For me, it was a matter of when, not if," she told reporters.
One of the patients came forward after learning someone they had spent time with in China had been infected with coronavirus, Dr Chant said.
Authorities will release the travel arrangements for one of the confirmed NSW cases, who was believed to be contagious while flying.
"We have asked the national incident room to pull details of those people that were on that flight and we are getting the flight details and seat details," Dr Chant said.
The other two men were not thought to be contagious while travelling.
Four additional coronavirus cases remain under investigation in NSW.
China has confirmed 41 deaths from the virus, while some 1300 people are now estimated to have the virus worldwide.
The illness has been confirmed other countries including Thailand, Japan, South Korea, Hong Kong, Singapore, France and the United States.
Australians are being urged not to travel to Wuhan or China's Hubei province.
Australian Associated Press