A State fund set up to support jobs in Ireland lost €750,000 on an investment because of a human error that wrongly categorised the money as euro when it should have been in dollars.
When the rate of exchange moved against the State body, it lost thousands because it failed to put in place a mechanism to offset a loss caused by a movement in currencies.
The investment was made by the State's Strategic Investment Fund, which is part of the National Treasury Management Agency (NTMA).
The issue was highlighted in a periodic report by the Public Accounts Committee (PAC), which questioned the agency about the "control weakness".
The report said: "The NTMA explained that the agency purchased a fund in dollars, but it was not designated or marked on the spreadsheet record as such. It was recorded as a euro fund.
"Subsequently, when the error was discovered, the dollar exchange rate had moved against the NTMA and the investment return was down €750,000."
The PAC was informed that the NTMA had corrected the weakness in its processes, which it said was caused by "human error".
The NTMA said it was confident that such a situation could not happen again.