Dr Gabriel Scally is raising serious concerns about the free movement of people at our ports and airports, due to the Covid-19 crisis.
It comes as the National Public Health Emergency Team meets this morning to discuss the outbreak.
Nearly 1,000 new cases were confirmed last night, bringing the country's total to nearly 10,700.
Dr Scally, who led the inquiry into CervicalCheck, says particular care is needed at ports and airports - even after the peak of the virus.
"Even if we get the numbers down across the island of Ireland, well it would be very susceptible to new cases coming in through ports and airports.
"that is a real issue, and I think that deserves quite a deal of attention.
"That free movement of people, without checks, without taking temperatures, without taking details, or without testing - that's something that really needs to be looked at."
