The Government has said it is working to establish the exact chain of events in relation to a flight carrying deportees from the US, which is understood to have stopped in Shannon Airport this week.
It follows a report in the New York Times that an aircraft with a number of people on board landed at the Co Clare airport on Tuesday night.
The newspaper said the flight landed in Shannon at around 9.39pm for around two hours, before continuing its journey to Djibouti.
The US Department of Homeland Security confirmed that it conducted a deportation flight to remove what it described as "some of the most barbaric, violent individuals illegally in the United States".
It said the eight men had been given final deportation orders and listed them as being originally from Cuba, Laos, Mexico, South Sudan, Myanmar and Vietnam.
Last month, Massachusetts Judge Brian Murphy ruled that the transfer of migrants to countries other than their own should not progress, until they were allowed to challenge such orders.
Judge Murphy said the deportations violated his injunction and he has ordered US immigration officials to keep the men in their custody, pending a further hearing.
The Department of Homeland Security described the court ruling blocking the removal orders as "deranged".
In the Dáil, Tánaiste Simon Harris said officials were liaising with their US counterparts in relation to the matter.
He said the flight in question was a civil aircraft and would not have needed diplomatic clearance to land here.
Mr Harris acknowledged there was "significant public interest and public concern" about the reports, which he described as "an evolving situation".
The Department of Transport regulates civil flights.
The Tánaiste said efforts were continuing to get full clarity about what may or may not have taken place.
Speaking earlier on RTÉ's Morning Ireland, Mr Harris said he has "no reason to believe that the procedures in place for the use of Irish airports by foreign aircraft has been breached by the United States", but added he was seeking more information.
Mr Harris was responding in the Dáil to Labour Party leader Ivana Bacik, who said there had been a "shocking revelation that Donald Trump's deportation flights are refueling in Ireland at Shannon Airport".
"These are deportation flights which are illegal, taking place in violation of a US court order," she said.
"In other words, an Irish airport has been used as an instrument to violate human rights," she added.
She said she understands that one of the planes in question is due to refuel at Shannon Airport on its return journey from Sudan.
The Department of Homeland Security said that due to security sensitivities, it cannot confirm the intended final destination to which the deportees are bound.
However, in a post on social media, the White House deputy chief of staff appeared to confirm the men were currently in Djibouti.
Stephen Miller said the judge's order was endangering the lives of US officials who had been told to retain custody of the deportees, without staffing or resourcing.
US flights stopping off at Shannon Airport to refuel have long been an issue of contention in Ireland, as politicians and activists raise concerns that it makes Ireland complicit in US military actions.
Protests have been held at the airport over the Iraq War, Western intervention in Syria, and more recently over US support for Israel during its military operation in Gaza.
In recent months, there have been reports that flights carrying munitions to weapons manufacturers and contractors in Israel have travelled through Irish airspace.
Permission is needed from the Minister for Transport to carry munitions over Ireland.
Mr Harris has said he does not believe that weapons are being flown through Irish airspace to Israel, but he said more international co-operation was needed to find out what is being flown above Ireland.
