Jobs Minister Frances Fitzgerald has said it is "completely unacceptable" that the corporate affairs watchdog might not have raised concerns about its understaffing.
Minister Fitzgerald said it is now important to determine whether other prosecutions might also fall victim to the same issues.
The Tánaiste was taking Dáil questions for the first time since the collapse of the Sean FitzPatrick trial, and her move to the Department of Jobs.
She said that claims of the office being under-resourced are seriously concerning.
“I would say they are completely unacceptable, and would say that they fell far short of the standard that we would want to see of impartial, unbiased and thorough investigation,” she said.
“They should have been impartial, unbiased and they should have been thorough.
“And as I say, I would consider them to be completely unacceptable.”