More than half the people coming to Ireland from abroad who should be self-quarantining for two weeks to avoid passing on Covid-19 are not answering phone calls checking on their whereabouts.
Figures reveal that from the end of May to the middle of June, as overseas holiday traffic increased, officials rang 684 new arrivals who had come here from abroad by plane or boat.
However, just 308 of the calls were answered - a mere 45pc, the figures obtained by the Herald reveal.
The worrying pattern of many overseas arrivals here going missing has been repeated over several weeks, the Department of Justice data revealed.
The self-quarantine is strongly advised but not mandatory
It comes as public health doctors reveal a resurgence in cases of the virus linked to foreign travel.
During June, a total of 31 cases of Covid-19 in Ireland were associated with travel from abroad after months when it posed a low risk of virus spread.
Chief medical officer Dr Tony Holohan repeated the advice which has been in place since the start of the pandemic to avoid all non-essential travel abroad.
"The World Health Organisation has warned that the global pandemic is accelerating," Dr Holohan said.
"In the past week, over 160,000 cases have been reported each day."
Earlier this week, Dr Holohan advised people who had booked foreign holidays to cancel them to reduce the risk of picking up the virus abroad and spreading it on their return home.
The Government is set to publish a list of countries next week which Ireland could set up air bridges with, allowing people from both countries to travel to each destination without quarantine restrictions.
Greece and Finland are expected to be among the countries included.
The advice will still be not to travel but if people want to go overseas they should restrict themselves to these countries.
However, it is highly unlikely there will be any mechanism for a refund for people who cancel holidays because the guideline throughout has been not to book non-essential trips overseas.
Dermott Jewell, of the Consumers' Association, said the Government needs to offer guidance to airlines and provide a fund so that holidaymakers who choose not to travel can get their money back.
Dr Holohan yesterday announced another three people had died from the virus, bringing the toll death toll here to 1,738.
Another six cases of Covid-19 were confirmed, which continues to be low despite the opening up of businesses during the exit from lockdown.
It brings to 25,477 the number of cases of the virus here so far.
The National Public Health Emergency Team will meet today to review the latest trends in the disease in advance of the list of air bridge countries being announced next week.
Meanwhile , the vast majority of adults believe that holidays to countries with high rates of Covid-19 should not be allowed, a survey has found.
Market research carried out by iReach found that nine out of 10 adults believe holidays to countries with high rates of Covid-19 should not be permitted.
The survey found those aged 55-plus feel even stronger about this, with 96pc of this age group believing holidays to these countries should not be permitted.