It has emerged that the former board of the Central Remedial Clinic has yet to confirm whether it will appear at the Public Accounts Committee next week.
The committee is due to discuss the financial issues at the charity at a hearing next Thursday.
HSE officials have already confirmed they will appear, but the clinic's former chairman Hamilton Goulding has yet to say if he will attend.
"There are a lot of questions for the old board still to answer," said committee member Shane Ross.
"The [administrator's] report mentioned missing files, and other issues which are outstanding, which undoubtedly we ought to ask them about."
The report of the interim administrator, published one week ago, found several "legacy issues" surrounding executive structure and pay.
The report also fond that HR files relating to two former chief executives "could not be located" and documents referred to in the minutes of board meetings were not themselves "always available".
"One anonymous note was received in the Interim Administrator’s Office alleging an inordinate amount of shredding in 2013," the section on record-keeping noted.
"The Interim Administrator could not verify if this was the case."