A sergeant was searched and a phone seized during the operation.
A garda station in Munster has been searched in relation to allegations of the leaking of Barry Cowen's drink driving case.
The Laois/Offaly TD was forced to step aside from his post of Agriculture Minister last July when details emerged of the 2016 incident.
Deputy Cowen questioned how the information ended up in the public domain as well as the details of the case on the record, leading to a GSOC investigation.
The Irish Daily Star reports that investigators seized a phone during the operation last week.
Another Fatality Following Offaly House Fire
New Laois Primary Schools Needed To Meet Future Demand
HSE Lacking "Integrity" And "Sincerity" In Offaly Hospice Fallout - Fergus McDonnell
Revenue Seize Contraband Worth Over €458K In Various Operations
Niall Horan Teases Irish Tour Dates
Midlands Meteorologist Explains Rise In Earth's Climate
Westmeath Entrepreneur Goes Global With 'The Raw Network'
BnM Granted Approval For 100m Offaly Wind Monitoring Mast
Longford Westmeath TD Criticises 'Hands-Off' Government
Evictions In Ireland Expected To Surge
Westmeath Man Avoids Jail For Dublin City Punch-Up
Midlands Man Uses Survival Skills To Rescue Missing Teenagers
Midlands Ireland Conference Celebrates Regional Transformation
Westmeath Man Calls for Support In Fundraiser After MND Diagnosis
House Prices On The Rise In The Midlands
Drug Convictions Soar In Midlands
Dog Has New Best Friend After Offaly Rescue
TII Pressured To Provide Update On Major Midlands Road Project
Edenderry Festival Lineup Revealed
Midlands-Based Student Takes Bronze At Culinary Contest