Children's Health Ireland (CHI) accepted €30,000 from a concession holder towards the cost of a staff Christmas party in 2022, the Public Accounts Committee (PAC) has heard.
Comptroller and Auditor General Seamus McCarthy, said it "raises concern about decision making".
He said his staff identified the funds in a CHI account and queried it.
He said the "explanation that was provided then gave rise to concerns".
Mr McCarthy said the related hospitality expenditure was not disclosed in the 2022 financial statements, "as was required".
The unreleased funding was returned to the concession holder following a query during the 2024 audit, he said.
He said when it was "brought to the attention of the board of the hospital, they decided to return the funding".
He said there were concerns around the event itself, "which should have been disclosed" in the governance statement, and the "propriety of accepting contributions from a concession holder".
Mr McCarthy said this "muddies the waters in terms of the competitiveness of the award of a concession".
Fine Gael TD Joe Neville asked if this is a "common occurrence".
It seemed to have been a one-off, responded Mr McCarthy.
Mr Neville said it was "bizarre" that the payment would be offered and accepted.
He said it could be seen as "almost like a kickback to the company".
