Four people in NSW and Queensland are being tested for the coronavirus, which has now killed 26 people in China.

Chinese health authorities confirmed there have been 830 laboratory-confirmed cases so far. Most of those cases were in the central Chinese city of Wuhan, where it's believed to have originated in December.

Flight crew and passengers arriving at Sydney International Airport from China on Thursday. Credit:James Alcock

On Friday four people in NSW were tested for the coronavirus. Two patients tested negative for the new virus on Friday afternoon.

Five other previous cases referred to NSW Health were also determined to be other illnesses.