RTÉ said in its statement that the payments made to Ryan Tubridy were recorded in a barter account.
A barter account is used in accounting to record the exchange of goods or services for other goods or services.
Examples could include football clubs making the use of a corporate box available to a company which provides it with crowd management services, or a local radio station being provided with company cars by a dealership in exchange for adverts.
Accounts for recording these transactions are often operated by brokerages, as part of an attempt by the parties involved to avoid unequal exchanges. These brokerages charge fees.
In its statement, RTÉ said two payments worth €150,000 in total were made to Mr Tubridy through a barter account in 2022. These payments related to the years 2021 and 2022 and were €75,000 each. €18,750 of that related to earnings for the first three months of 2023.
Inclusive of fees incurred through the process, this resulted in a cost to RTÉ of €230,760.
Between 2017 and 2019, Mr Tubridy separately received a total of €120,000 more in payments from the broadcaster than had been previously publicly stated. The reasons for these payments are currently under investigation, RTÉ said.
The payments made through the barter account were flagged by auditors and prompted the wider review conducted by Grant Thronton.
The auditors concluded RTÉ had guaranteed and underwritten Mr Tubridy an additional income of €75,000 in the relevant years, payments it did not disclose in its statements on top ten earners.
The RTÉ statement said it was intended that this income would be covered by a commercial partner. It was to be covered as part of the barter account arrangement.
In exchange for a commercial partner paying Mr Tubridy for €75,000 worth of services in 2020, RTÉ was to provide the commercial partner with a credit note for – typically - advertising for the same value.
When the commercial partner did not renew the agreement during the pandemic, as RTÉ had underwritten the agreement, the payments were instead made directly by RTÉ to Mr Tubridy.
It appears those payments were made through the barter account, despite no involvement from the commercial partner.
In its statement, the RTÉ board said it has taken steps to ensure there is "no recurrence of these matters," including "bringing the Barter Account within the control of the Finance function."
Key questions RTÉ needs to answer over Tubridy payments