The Blaney inquiry into potential misconduct by members of the Institute of Chartered Accountants cost the organisation €623,000 last year.
The inquiry was instigated in 1996 and is investigating several individuals and firms named in the McCracken Tribunal examining payments to Mr Charles Haughey. It completed its work in 2000, but publication of its findings has been held up by a number of internal appeals.
The organisation expects to publish the results of both the inquiry and the appeals shortly, but warned yesterday that "possible judicial review proceedings may ensue out of these matters".
The disclosures were contained in the ICAI's annual report released yesterday. The cost of the inquiry represents a significant reduction on the €1.94 million spent in 2001.
The ICAI also expects a committee of inquiry looking into the role of members of the profession in the collapse of Northern Ireland engineering company Powerscreen to complete its work shortly.
"Hopefully this marks the end of what has been a very long, difficult and expensive road for the Institute," according to Mr Brian Walsh, the chief executive of the institute.
The full cost of the inquiries has not been quantified and the organisation's accounts warn that a contingent liability exists in relation to the cost of "public concern" cases.
Mr Walsh's remuneration is also disclosed in the report. He earns €160,000 per annum.