The FAI have passed on to FIFA an anonymous tip that up to six members of the Andorra squad that the Republic of Ireland are due to face in a World Cup qualifier on Wednesday night are ineligible.
The allegation is that midfielder Marc Bernaus has already played for Spain at competitive junior level while five other unnamed players do not have Andorran passports.
Bernard O'Byrne, chief executive of the FAI, said: "This information has been sent to us anonymously by fax to Dublin and my initial suspicion is that it is a complete red herring.
"I would be absolutely amazed if it were true.
"But we feel we are obliged to pass it on to the FIFA commissioner and let him deal with it before the game because we certainly do not want to become embroiled in anything afterwards.
"It is a very awkward situation for us."
Checks have revealed that a Marc Bernaus did play for Spain against Ireland in 1997 in the World Under-20 Championships in Malaysia.
PA