A man is being treated at Belfast's Royal Victoria Hospital for symptoms associated with coronavirus, which has so far caused 18 deaths in China.
The BBC understands he travelled to Northern Ireland from the city of Wuhan where the infection outbreak began.
It is believed the man is being treated in an isolation ward as a precautionary measure and results of tests for the virus are due back in 24 hours.
The Belfast Health Trust has declined to comment.
It is understood that the patient arrived from Wuhan at the weekend.
The city is one of two in China which are currently in lockdown to halt the spread of the virus.
The man being treated in Belfast is believed to have been admitted with a high temperature.
It is thought clinicians took the immediate step of placing him in isolation following advice from health authorities.
The Public Health Agency (PHA) in Northern Ireland said it is keeping abreast of the changing situation around the virus.
Dr Philip Veal, PHA consultant in health protection, said people who developed symptoms within two weeks of returning to Northern Ireland from Wuhan should "not panic", but contact their GP by telephone.
Dr Veal said special measures had been implemented to transfer those most at risk of coronavirus to hospital.
"We do not expect it to become widely established in Northern Ireland," he said.
Dr Veal said he would "strongly recommend" anyone who has not taken up their offer of a flu jab to get vaccinated.
Wuhan, a city of 11 million people, has gone into lockdown, with planes, trains and public transport in the city suspended.
Similar measures will take effect in nearby Huanggang, a city of more than seven million, as of midnight.
Any suspected cases have to be isolated and staff dealing with them must wear protective clothes including gloves, masks and goggles.
Elderly people and those with underlying health conditions are particularly at risk.