Two men and a woman have been arrested as part of the investigation into the kidnapping and torture of Quinn Industrial Holdings director Kevin Lunney.
They are being held at garda stations in Kells, Cavan and Monaghan.
Other searches were carried out in Cavan, Longford and Dublin.
When asked for a statement, the Garda Press Office said: "Gardaí this morning, 14th November 2019, have arrested a number of people in relation to the abduction of Kevin Lunney on 17th September 2019.
"A male in his 20s and a male in his 40s are currently being detained under section 50 of the Criminal Justice Act, 2007.
"A female in her fifties is being held under Section 30 of Offences Against The State Act, 1939.
"An Garda Síochána is not providing any further information at this time."
The Garda spokesman added: "An Garda Siochana continues to appeal to any person who has any information, no matter how insignificant it appears, on this vicious criminal attack or any other criminal activities which have taken place in the Cavan/Fermanagh border area over recent years to contact An Garda Siochana at Cavan Garda station on 049 4368800, the Garda Confidential Line on 1800 666 111, or Crimestoppers on 1800 25 00 25 or any Garda station."
Gardaí and the PSNI have established a joint team to investigate a campaign of intimidation, including death threats, targeting the QIH directors.
Last week the chief suspect in the investigation, Cyril McGuiness, died during a police raid in the UK.