An Irish couple returning from the coronavirus-hit Diamond Princess cruise ship in Japan may face another two weeks of quarantine in the UK if they are airlifted on a British repatriation flight.
The Department of Foreign Affairs said it is assisting with travel for uninfected Irish passengers who are free to leave the vessel in Yokohama.
It is unclear what kind of transport is involved but it could be an evacuation flight planned by the British foreign office from Tokyo to England later this week.
The plan is to quarantine the passengers for 14 days in the NHS facility near Liverpool which also housed people flown back to the UK from the Chinese city of Wuhan.
Two Irish citizens who normally live in Germany remain in hospital in Tokyo where they are being treated for the coronavirus.
The other four Irish include the couple from Co Meath and two crew members.
The two crew will continue to work on the ship until everyone is discharged.
Hundreds of passengers are now in the process of disembarking from the cruise but another 79 new coronavirus cases were detected yesterday.
A Japanese disease expert, Kentaro Iwata, described the ship's quarantine as a "major failure", "completely inadequate" and a "mistake".
He had to put himself in a 14-day quarantine for fear of infecting his family after a brief visit on board the vessel, which was placed in quarantine until yesterday but has seen cases of infection mount during that time.
Prof Iwata, an infectious diseases expert at Kobe University, said the ship was completely inadequate in terms of infection control.
He said there was "no distinction between the green zone, which is free of infection, and the red zone, which is potentially contaminated by the virus".
"I was in Africa dealing with the Ebola outbreak," Prof Iwata said. "I was in other countries dealing with the cholera outbreak. I was in China in 2003 to deal with Sars... I never had fear of getting infection myself."
However, Japanese official Shigeru Omi, a former World Health Organisation regional head advising the government, said the quarantine had "a very positive effect" on reducing infections.
"The majority of the infections, we believe, occurred before the date when the quarantine measures started," he said.
Meanwhile, there was relief for another seven Irish citizens, two of whom live in Ireland, who were another cruise ship.
That ship, the Westerdam, which is moored off Cambodia, has given the all-clear to passengers.
Holland America, which runs the Westerdam, said test results "provide the required clearance for remaining guests to begin their onward journey home".
The ship was quarantined after one of hundreds of passengers who disembarked last Friday tested positive for the virus. Two of the passengers were Irish and they returned to Ireland at the weekend.
They were not exit screened before leaving Cambodia but have been in contact with the HSE since and are in self-isolation, following precautionary protocols.