Alan Dukes tried to "terminate" the appointment of a senior Department of Finance official who was seconded to IBRC by the Finance Minister, Michael Noonan, the Sunday Independent can reveal.
In a leaked letter to the department's secretary general John Moran, the IBRC chairman Mr Dukes severely criticised the role of the official and wrote that his involvement with the bank was being "terminated at close of business today".
The letter, which is dated 28 January 2013, suggests that there was deepening animosity between the State-owned bank and the department in the days before the special liquidator was appointed to the IBRC.
The Sunday Independent can also reveal today that the special liquidator, KPMG, has already received more than €70m in professional fees related to the liquidation of the former Anglo Irish Bank.
A report published by the Department of Finance last month shows that KPMG received €71.3m - or nearly half of the almost €160m paid out in fees from February 2013 to December 2014.
The appointment of KPMG to carry out the review of the sale of Siteserv to a company owned by Denis O'Brien has been rejected by Opposition TDs, who have pointed out that the special liquidators also acted for Siteserv.
Yesterday Fianna Fail leader Micheal Martin said the firm, which supervised the controversial payment of €5m to Siteserv shareholders, cannot conduct "an independent review" of the sale.
In his letter, Mr Dukes, a former Fine Gael leader, wrote that the official's secondment was proposed on a six-month basis to a role that could help "build bridges between the Bank and the Department of Finance".
The extraordinary letter from the then chairman of the State-owned bank to the department's secretary general, John Moran, reveals the rapidly worsening relationship between both civil servants and bankers days before the bank was liquidated.
The Minister for Finance stood down the board of IBRC and appointed a special liquidator on February 6, 2013.
The letter is further confirmation of the increasingly fraught relationship between the Department of Finance and the IBRC, which was disclosed in documents released under the Freedom of Information Act last week.
Mr Moran, who is currently working as a consultant, this weekend said that personal attacks made against civil servants who asked questions about the Siteserv deal are "regrettable".
Yesterday, a spokesman for the Department of Finance said the official who was seconded to IBRC remained in his role there until the bank was placed into liquidation on February 6, 2013.