FAI chief executive John Delaney has confirmed he gave the governing body a 100,000 euro loan to "aid a very short-term cash flow issue".
The FAI stated the "bridging loan", given in April 2017, was repaid in full to Delaney two months later.
"I acted in the best interests of the Association at a time when immediate funding was needed," said Delaney.
"This loan had no impact on the full financial position or performance of the Association for the year."
He added: "It was a matter of timing. The monies received from EURO 2016 were utilised in that year's budgets as outlined in the financial report to the 2017 AGM.
"As CEO, I hold regular meetings with our Director of Finance regarding the state of our finances and all items arising are conveyed to our Board at our monthly meetings.
"This was the case in 2017 when I acted in good faith for the benefit of the FAI and will continue to do so."
It comes as the FAI announced that a report and recommendations on its governance are expected in early April.