More than 40% of the €22bn of loans owed to IBRC at the time the Special Liquidator was appointed over two years ago had an interest rate of 2% or less, while €16bn of the total was accompanied by a rate of less than 3%.

The figures were released to Fianna Fáil finance spokesman Michael McGrath by Finance Minister Michael Noonan in response to a parliamentary question.

“Almost three quarters of the loans in value terms had an interest rate of less than 3%,” said Mr McGrath. “On the face of it, the interest rates seem to be extraordinarily low and it will need to be established whether these rates relate to historic loan agreements entered into by the old Anglo-Irish Bank or whether they reflect decisions made by management since the bank was nationalised in 2009.

“Many mortgage holders paying over 4% or 5% on loans and SME owners paying 7% or 8% on commercial term loans will view these IBRC rates as mouthwatering.”

The figures also reveal that 166 loan accounts worth a combined €399m were charged less than 1% interest.

IBRC’s special liquidators said yesterday that loans with a rate of less than 1% related to distressed loans where the loan was restructured or where the borrower was in liquidation or administration and the prospect of any future recovery was remote.

A commission of investigation into IBRC was established earlier this month following the controversy surrounding the sale of Siteserv to the Denis O’Brien-controlled Millington for €45m in March 2012.

The sale resulted in a loss to the State of just over €100m.

The inquiry will examine up to 40 transactions where there was a capital loss to taxpayers of €10m or more.

The commission’s remit also extends to investigating whether preferential interest rates were extended to certain borrowers.

Independent TD Catherine Murphy claimed in the Dáil a number of weeks ago that Mr O’Brien was paying an interest rate of 1.25% when, she suggested, a rate of 7.5% should “arguably” be applied.

Mr O’Brien denied the claims and accused Ms Murphy of “peddling” false information.

Mr McGrath said yesterday that he had decided to refer the information provided to him to Judge Daniel O’Keeffe, who is chairing the commission of investigation.