The latest case came a day after Hong Kong Chief Executive Carrie Lam declared the outbreak an emergency and rolled out a series of measures to prevent further infection, reports the South China Morning Post newspaper.
The patient, in Ruttonjee Hospital, was diagnosed as having the virus on Sunday, and would be transferred to Princess Margaret Hospital, the sources said, adding that he was set to undergo further tests.
The Hong Kong resident with fever symptoms had been to Wuhan, the Chinese city at the epicentre of the outbreak, and returned home via high-speed rail.
It is not immediately known when he returned from China but a medical source said he had gone to Ruttonjee Hospital after being bitten by a dog.
The patient is the second resident of Hong Kong confirmed as having the infection, out of a total of six cases detected in the city so far.
Secretary for Food and Health Professor Sophia Chan said on Sunday that the government was looking at whether to increase border controls, including shortening operating hours at checkpoints, the South China Morning Post reported.
Meanwhile, Macau confirmed three new cases of the Wuhan virus on Sunday, raising its total to five.
Officials from Macau said one of those infected was a 58-year-old Wuhan resident, who arrived in the casino hub via Hong Kong on a ferry.
The disease has already spread to a dozen other countries with Canada confirming its first case on Saturday after a patient in Ontario tested positive. The man is said to have travelled from China recently.
Besides Canada, the cases reported outside China were five each in Thailand; four in Australia; three each in South Korea, Taiwan, Singapore, Malaysia, Nepal and France; two each in Japan, the US and Vietnam.
The death toll due to the novel coronavirus (2019-nCoV) outbreak in China has increased to 56, while the number of infected persons were 1,975, the country's National Health Commission said on Sunday.
Chinese President Xi Jinping has warned that the spread of the deadly illness was accelerating.
( With inputs from IANS )