A man was today being questioned about more than 150 hoax bomb alerts in Omagh since the 'Real IRA' atrocity in August 1998 which claimed 29 lives.
Garda detectives swooped on a house in Letterkenny, Co Donegal following a major cross-border investigation with officers from the Police Service of Northern Ireland.
A 44-year-old man was arrested and taken for questioning in connection with making hoax bomb calls.
Security sources have confirmed officers want to speak to him about a series bomb warnings following the August 1998 outrage in the Co Tyrone market town.
"More than 150 hoax calls were made after the real attack," one said. "We even set up a joint investigation team to try and find out who was responsible."
A Garda spokesman confirmed the man was arrested under Section 30 of the Offences Against the State Act 1939.
He has been detained at Lifford Garda station where he can be held for up to 72 hours.