Ryan Tubridy stepped down as host of the Late Late Show earlier this year.
RTÉ paid Ryan Tubridy 345,000 euro more than declared from 2017 to 2022.
The state broadcaster has described it as a "serious breach of trust".
A review was carried out by Grant Thornton into RTÉ's accounts - which was discussed by the board of the broadcaster on Monday.
It found payments totaling 345,000 euro were paid to Ryan Tubridy between 2017 and 2022 - over what was made public.
The review found RTÉ had guaranteed additional payments to the former Late Late Show host through commercial partners - in exchange for appearances.
Figures released by the broadcaster show Tubridy was paid in excess of €500,000 between 2017 and 2022 - despite his salary being declared below half a million.
Ryan Tubridy stepped down as host of the Late Late Show earlier this year.
The RTÉ board has apologised
Suspected Cannabis Worth €1 Million Seized From Ashbourne Warehouse
Mind Your Dogs: Surge In 'Stolen to Order' Thefts Alarms Locals
Second Refugee Housing Project Halted in a Week: First Manor Kilbride, Now Westmeath
A Private Developer In Westmeath Has Been Stopped From Setting Up Modular Housing For Refugees
Digital Driving Licence Are Coming To Ireland
Inspections Of Centres Housing International Protection Applicants Found Various Levels Of Non-Compliance
Full Road Closure And ‘Severe Delays’ On M50 Following Serious Crash
TikTok Under Fire: Urgent Plea For Algorithm Change To Safeguard Youth From Disturbing Suicide-Related Content
