Two of the four NSW coronavirus patients have recovered from the potentially lethal infection and have been discharged from hospital, according to health authorities.

Key points: There have been nine confirmed cases of coronavirus in Australia

There have been nine confirmed cases of coronavirus in Australia Two men in NSW detected with the virus are now deemed infection-free

Two men in NSW detected with the virus are now deemed infection-free There are 20 potential cases being investigated in the state

NSW chief health officer Doctor Kerry Chant said the men were no longer infectious and had been released.

"Their symptoms have resolved completely," Dr Chant said on Thursday.

"As an added precaution we have undertaken testing to confirm there is no virus detectable in samples taken from those individuals.

"They acquired the virus, they got better, and now they're not infectious."

Both of the discharged men had arrived in NSW from China: a 35-year-old man travelled to Sydney from Shenzhen and a 53-year-old male flew to Sydney from Wuhan.

A 21-year-old female student from the University of New South Wales and a 43-year-old man remain in isolation.

Authorities in NSW have been ramping up testing for the virus in recent days, encouraging recent visitors to China to come forward even if their symptoms are mild.

Dr Chant said she would not be surprised if further cases of coronavirus were confirmed in NSW, where currently 20 possible cases are under investigation.

"I wouldn't be concerned if I found another case — that would reflect the veracity of our screening processes," she said.

Nine cases, including the two men who have been discharged, have been confirmed in Australia — four in NSW, three in Victoria and two in Queensland.

On Thursday evening, Queensland authorities confirmed their second case of novel coronavirus via a statement from chief health officer Jeannette Young.

Dr Young confirmed the patient was a 42-year-old woman from the virus epicentre of Wuhan in China and that she had been travelling in the same tour group as the 44-year-old man who was the first recorded case in the state.

Dr Young also said authorities were looking to trace people who may have come into contact with the infected duo, either at the Gold Coast hotel they were staying in or on the January 27 Tigerair flight the man travelled from Melbourne to the Gold Coast on.

Victoria also recorded its third case of coronavirus on Thursday as a woman from Hubei province in China.

The woman, aged in her 40s, was in a stable condition in isolation at the Royal Melbourne Hospital, a statement from Victoria's Department of Health and Human Services said.

Hundreds of Australians are presently in Wuhan awaiting a potential evacuation from the Federal Government to Christmas Island, where they would be placed into quarantine for a fortnight.