The party's internal procedure has been halted with gardaí taking up the case.
The Sinn Fein Leader is characterising the complaint made against Laois Offaly TD Brian Stanley, which has been passed on to gardaí, as "serious".
Mr Stanley has resigned from the party claiming he was unfairly treated by an inquiry into a complaint against him.
Mary Lou McDonald says the internal process has now been suspended - Deputy Stanley says the process was seriously flawed.
Speaking with Will Faulkner on Midlands Today, she says she couldn't outline the details of the complaint:
Offaly Boxer Serves Up ‘Boxer Bites' Series On Social Media
Gardaí Seize Over €200k Worth Of Drugs In Carlow
Defence Boost Won’t Solve Personnel Shortages - Declan Power
Offaly Biodiversity Project Reopens For Year Two
New Midlands Hospice A Boost For Offaly - Tony McCormack
New National Minimum Wage To Take Effect On New Year’s Day
Fatal Road Collision Claims Life Of Man In His 40s In Midlands
People Urged To Be Kind To Themselves When Setting New Year Resolutions
Defence Expert Links Trump’s Stance On Iran And Venezuela
Carlow Dog Attack Leaves Woman In Hospital With Serious Injuries
Gardaí Issue Appeal For Information On Black Car Involved In Offaly Arson Attack
Kerry v Dublin - A Rivalry That Revived The GAA
Offaly Acts Set To Feature As New Year's Festival Celebrations Kick Off
Zelenksyy Issues Warning Over Donbas Compromise
Revenue Operations Lead To Seizure Of €500k Worth Of Cannabis
Gardaí Issue Safety Appeal Amid High number Of Festive Motoring Offences
Midlands Cold Snap Incoming
Rían, Jack, Emily And Grace Top Midlands 2025 Baby Names List
Wellness Soul Circle Coming To The Midlands
Mother Of Offaly Arson Attack Victim Appeals For Justice