The Department of Health will step up medical surveillance at the airport from Wednesday, requiring all arrivals to undergo a Covid-19 test.

They will be taken straight away to the test centre at Asia World Expo for their saliva samples to be collected before they will be allowed to go home for mandatory quarantine. Test results usually come back in three days.

But people arriving from Britain will have to stay at the test centre until their test results come back - because almost 70 percent of the nearly 360 imported Covid 19 cases over the past two weeks have come from the United Kingdom.

The Department of Health said it believes this is a more effective way to identify possible cases and their close contacts, given the experience of people who recently returned from high-risk areas such as Peru.

Meanwhile, people who return from Hubei province via land crossings will be given a test kit to collect samples at home from Wednesday.