The video Stephen Kenny showed to Ireland players before the England game was three minutes long, the first 35 seconds of which depicted moments in Irish history.
The 1916 rising and the Proclamation of the Republic were referenced at the start of the montage.
FAI chiefs are investigating whether this was suitable material to be used as a motivational tool before the 3-0 defeat at Wembley.
David Kelly’s goal in the 1995 game at Lansdowne Road that was abandoned because of rioting English hooligans was also shown.
And so too was Ray Houghton’s winning header at Euro 88 when Jack Charlton’s side famously beat England 1-0 before Kenny addressed the players himself.
No official complaints were made at the time.
But one member of the travelling Irish party - not a player - is understood to have raised the matter subsequently with the FAI by querying the suitability of the video.
In a statement, the FAI said it was: “Aware of issues surrounding content shared with our senior men’s team ahead of the friendly against England at Wembley.”
The statement continued: “The FAI is already looking into this matter internally as a matter of urgency to establish the facts.
“The FAI has no further comment to make at this time.”
The video was shown before a team meeting in Ireland’s hotel in London on the day of the game, where only players and senior playing staff are allowed to attend.
Accounts of the nature of the three minute clip - intended by Kenny to motivate the players - have varied today.
It was described as both ‘overtly political’ while another source who saw the short video said tonight it was “not remotely offensive”.
Goalkeeper coach Alan Kelly controversially pulled out of the trip to Dublin for the Bulgaria game on Wednesday.
He had been with the squad in the UK for the England and Wales games but was replaced for the Dubin leg by Dundalk coach Steve Williams.
According to the FAI, Kelly is asthmatic and decided to stay in England because of rising coronavirus fears in the Irish camp after four players tested positive.
