He justified his €27m pension pot on the grounds that he had taken over the management of his own pension fund in the early 1990s and had himself, through investment, increased the fund nearly tenfold.
The inquiry returns from its summer break tomorrow morning when former Irish Nationwide CEO Michael Fingleton will give evidence.
Mr Fingleton left the company in late 2009 and Irish Nationwide received a €5 billion bailout from taxpayers before later being closed by the Government.
Other lines of inquiry include the liquidity versus solvency debate, the appropriateness of the bank guarantee decision, the decision to recapitalise Irish banks, and the appropriateness and effectiveness of the regulatory regime.
The Banking Inquiry was set up by the Irish parliament in May 2014 to examine the reasons why the Republic of Ireland’s banking sector collapsed in 2008.
In a statement on Tuesday, the inquiry said it had agreed to withdraw its direction to Mr Casey to attend public hearings this week.
“Because of the competitive nature of the market I believe that no single bank could have prevented a property bubble”.
He said it had cost the Society about €3m by his own estimation or €4m if the view of some experts was to be taken.
He added the European Central Bank also had the power to force the Irish regulator to take any necessary action but said “none of them chose to do so”.
The controversial former chief executive is expected to tell the inquiry that the building society was still solvent on the night of the guarantee.
Mr Fingleton said there was “no basis or evidence” by the pillar banks on which to push for the nationalisation of INBS.