Two Aer Lingus staff were on board an Air France flight which disappeared en route from Rio de Janeiro to Paris yesterday, it emerged this afternoon.
Their nationalities have not yet been confirmed, but Aer Lingus confirmed it is working closely with their two respective embassies.
Three young Irish doctors were also among the 228 passengers now feared dead.
Jane Deasy from Dublin, Eithne Walls from Belfast and Aisling Butler from Tipperary were recent graduates of Trinity College.
Metal debris, believed to be from the jet, has been found in the Atlantic Ocean 400 miles northeast of Brazil.