Chinese tourists in Australia are scrambling to extend their visas, fearing they could become infected with coronavirus if they return home.

Key points: Migration agents say they have been overwhelmed with requests for help

Migration agents say they have been overwhelmed with requests for help A total of 562 people have died from coronavirus in mainland China

A total of 562 people have died from coronavirus in mainland China More than 1.3 million Chinese nationals visited Australia last year

The number of confirmed cases of the deadly bug is almost 25,000 worldwide, and the World Health Organisation (WHO) last week declared coronavirus a global health emergency.

Qantas has also suspended flights to mainland China indefinitely.

Chinese nationals Jinfeng Wang and Xikun Zhang were on holiday visiting their daughter in Melbourne, when the coronavirus outbreak hit the headlines.

They 51-year-old and her husband have got two months left on their tourist visas, but must leave Australia after that.

"I'm really worried. If we return to China there is a high risk of getting infected," Ms Wang said.

The couple have hired a migration agent in a bid to extend their stay, and they're not the only ones.

Jennifer Zhu, a migration agent in Sydney, said her team had been working overtime to deal with the backlog of inquiries.

"A lot of them are very urgent due to the remaining days on their visas," she said.

"Some of them might only have a few more days before they must leave and they need professional advice instantly."

In the 12 months to September 2019, more than 1.3 million Chinese nationals visited Australia — about 950,000 of which came for holidays or to visit family.

Professor Rodger Fernandez from Victoria University's College of Law and Justice said Chinese tourists could make a good case to extend their stay.

"There are compelling circumstances affecting their ability to travel which is clearly beyond their control," Professor Fernandez said.

Mr Zhang said he and his wife were prepared to continue travelling to other countries, including New Zealand, in a bid to avoid returning to their home at Harbin, in northern China.

"Ideally the Australian Government will allow us to extend our visa until the coronavirus is under control and then we will go home," he said.

The Department of Home Affairs was contacted for comment.

Jeremy Fernandez will host a 30-minute special on coronavirus on Friday, February 7 from 7.30pm AEDT on News Channel, featuring a guest panel, explainers on how the virus unfolded and myth-busting the misinformation. The special will be repeated on ABC TV at 10pm.