ALEXANDRIA, Va.  —  An FBI counterterrorism team has found documents in Dublin, Ireland, linking Zacarias Moussaoui to an Al Qaeda cell there and one of Usama bin Laden's money men, Fox News has learned.

U.S. investigators say there is mounting evidence of an Al Qaeda presence in Ireland that has to this point gone largely unmentioned.

Numerous government sources say a lengthy investigation involving Irish, British and U.S. law enforcement has been under way into a mosque outside Dublin. Dozens of people in Dublin and surrounding areas are under investigation for providing false travel documents and cash to members of Al Qaeda.

U.S. investigators say the documents seized in Dublin associated Moussaoui with the false documents operation and an Al Qaeda operative who has supplied cash to terrorists-in-transit named Mustafa Ahmed al-Hisawi.

Al-Hisawi is a Saudi businessman who was identified earlier this year by the FBI and Treasury Department as an Al Qaeda cash courier.

Sources say documents were found in an apartment in the "Donnybrook" suburb of Dublin near the mosque. The apartment once housed offices of the Mercy International Relief Agency, a defunct bin Laden-sponsored front charity.