The Health Service Executive (HSE) says it may be necessary to call the gardaí to discuss financial arrangements at the Central Remedial Clinic (CRC).
It has emerged that €700,000 was taken from the fundraising arm of the CRC to pay the retirement lump sum of former CEO, Paul Kiely.
The PAC has heard that the pay-off to Mr. Kiely was over twice the amount previously disclosed.
He was given a retirement payoff of over €473,000, which is well over the €200,000 he told the Committee about last month.
Barry O'Brien from the HSE said the agency would do everything necessary to ensure proper financial oversight.
He says outside agencies could be brought in for advice on what to do next.
The Independent TD - and member of the Public Accounts Committee (PAC) - Shane Ross, has said revelations at the payout of the former CRC chief executive are 'utterly horrifying'.
He has described the affair to Newstalk Lunchtime as "a horror story".
The successor to Paul Kiely as chief executive of the CRC - Brian Conlan - said he was not aware of the arrangements for Mr. Kiely's pension.
He said he did not know the €700,000 had been used for Mr. Kiely's pension and that he assumed the arrangements had been taken care once he took over.
The HSE took over the running of the clinic in the aftermath of the top-ups controversy towards the end of last year.
HSE Chief Tony O'Brien has now written to the PAC about what he calls 'significant issues' they have over the package approved for Paul Kiely, who retired last year.
He says the arrangements seem to be at 'variance from the understanding the committee may have gained' at a hearing attended by representatives of the CRC board of governors last month.
Pictured above: Former CRC CEO Brian Conlan