The Garda Commissioner is holding a special meeting of security and intelligence officers in Garda Headquarters this morning after it was discovered that an Irish identity card was found on one of the three London terrorists who attacked the city on Saturday night.
RTE report that Gardaí confirmed the attacker lived in Ireland for a while, but was not known to them.
He is believe to have been of Moroccan origin, and was legally married to a woman from Scotland.
The man lived in Dublin while in Ireland, and was more than likely legally resident.
Gardaí are working with the British security and intelligence agencies to gather information on the attacker and his life in Ireland, and this morning's meeting will review security arrangements in the country.
The Department of Justice issued a statement on the likelihood of a terror attack in Ireland, saying:
"The expert threat assessment is that while an attack here is possible it is unlikely and that there is no specific information in relation to any threat to Ireland from international terrorism.
"That said the level of threat from this source is kept under constant and active review by An Garda Síochána."
The attacker is believed to have lived in Rathmines as recently as just one year ago.