The Irish Medical Organisation has confirmed that its outgoing chief executive's pension entitlements could have topped €25m had he stayed on.
George McNeice, 52, retired as chief executive before Christmas with accrued entitlements totalling €20m.
Following negotiations, Mr McNeice agreed to settle for a package totalling €9.7m.
That settlement includes a termination payment of approximately €1.5m.
Around 150 of the IMO's 5,000 members attended an EGM in Mullingar today to hear details of the controversy.
IMO President Dr Paul McKeown told them that a full independent audit had been commissioned, as well as a review of corporate governance.
Dr McKeown said that he shared the fury of members about the controversial pension arrangements.
Some members said they were considering leaving the organisation in protest.
Mr McNeice was earning around €500,000 a year at the time of his departure, with significant bonus payments.
IMO legal advice was that Mr McNeice's contract was valid and enforceable.