The head of human resources at Aer Lingus was detained after she used a boarding card for a flight she was not getting on, to get "airside" at Dublin Airport.
The airline has apologised to the Dublin Airport Authority for the incident, which will now be the subject of an inquiry by the airline and by the authority. An inquiry by the authority automatically follows security incidents at the airport.
Ms Liz White was due to attend a meeting yesterday in the "airside" part of Dublin Airport - the aircraft zone separated from the public areas by security checks.
But when she tried to get through the normal employee access route, she was refused entry because her employee pass was out of date. She then secured a boarding pass which she used to get access to the meeting, going through the normal security checks that apply to people intending to travel.
She was subsequently detained by airport police.
"She was using a boarding card for a flight she was not getting on to and she was detained. The system worked," said one source at the airport.
A spokeswoman for Aer Lingus said Ms White had now been issued with a new employee identification card that was in date.
She said the airline wished to apologise to the airport for any inconvenience caused as a result of the incident, which it regretted and which would now be inquired into.