Questions have been raised as to why a US surveillance plane spent several hours over Ireland earlier this week.
The plane, which made seven trips across the country on Tuesday, flew over Dublin, Shannon and Cork before returning to Dublin again in a triangular formation for five hours.
The Irish Aviation Authority (IAA) confirmed the flight, saying that: "A US military aircraft, with a pre-filed flight plan, operated in Irish airspace on Tuesday with approval from the Department of Foreign Affairs ."
The ‘clandestine’ flight was spotted by a Newstalk listener using the Plane Finder app,
The plane's transponder - which sends information to receivers on the ground – initially showed it to be a Boeing E6 Mercury.
This particular type of plane is used by the US Navy as an airborne command post and communications relay – mainly to convey instructions to its submarines.
However, it is now believed it may have been a Boeing E3 Sentry aircraft.
Commonly known as AWACS, this aircraft is deployed by the United States Air Force and is used an all-weather surveillance, command, control and communications vehicle.
According to the IAA, the plane stayed at a constant 28,000 feet throughout its journey over Ireland.
The Department of Foreign Affairs said: "Under long-standing arrangements we permit US military aircraft to overfly Ireland without seeking prior permission provided they are unarmed, carry only cargo and comply with navigational requirements".
It is understood 13 such flight-overs took place in August.
Speaking to Newstalk Lunchtime, security analyst Dr Tom Clonan said the most likely explanation for the flight was “[Ireland has had other visitors to our airspace in recent times.
“We had Russian aircraft bombers enter our controlled airspace recently down the west coast...and in the last number of years, with the Ukraine and rising tensions in the Balkans, some of the old Cold War rhetoric has found its way back into the international foreign relations narrative".
The US embassy in Dublin added: "[Our] government is appreciative of the Irish Government's policy of granting permission on a case by case basis for the transit of US service members and aircraft through Ireland.
"The US government appreciates and respects the conditions under which planes can utilize Irish airspace in accordance with Irish law.”