Taoiseach Enda Kenny has said Minister for Finance Michael Noonan's acted "entirely appropriately" with regard to the National Asset Management Agency's Northern Ireland loan book.

The Oireachtas committee that examined the sale of the loan book, known as Project Eagle, has concluded the agency's strategy was "seriously deficient".

The report by the Public Accounts Committee also found it was not "procedurally appropriate" for Mr Noonan to meet with Cerberus, the investment firm that ultimately bought the portfolio, as it could have given the perception of preferential treatment.

Mr Kenny said Mr Noonan had acted "entirely appropriately" throughout.

He also questioned why the minister was not asked directly about the issue when giving evidence to the committee.

"The PAC has always been an independent committee of the Oireachtas and I respect that, but Michael Noonan has acted entirely appropriately in this matter," he said.

"He went before the committee in a voluntary capacity, he spent five hours in front of the committee, he was asked no question about this and clearly his own letter that is included in the report points out the distinction between the role of the minister for finance and the commercial activities of NAMA.

"Michael Noonan has acted entirely appropriately here.

"I don't wish to make any comment of the activities of the Public Accounts Committee except to say that this is a disputed report."

Mr Noonan has said he was disappointed that "unjustified and unfounded views" made their way into the final report.

"I refute absolutely the validity of any suggestion that I or my officials acted inappropriately in meeting with Cerberus in March 2014," he said.

Fianna Fáil's finance spokesperson has said it was "unwise and ill-judged" of Mr Noonan to go ahead with a meeting with senior officials from Cerburus on the eve of the closing bids for Project Eagle.

Michael McGrath added that there was nothing to suggest that Mr Noonan influenced the final decision made by the NAMA board but it left him open to the accusation or perception that something untoward was happening.

Speaking on RTÉ's Today with Sean O'Rourke, Mr McGrath described it as a "poor decision" and one he should "just take on the chin".

He said it was quite remarkable that Mr Noonan did not mention the meeting to the Oireachtas committee examining the sale of the loan book.

Mr McGrath said the sales process did not meet the standard that you would expect for a transaction of this magnitude.

He said the case for a proper commission of investigation into the sale is "indisputable at this point" given that serious shortcomings in the process have been identified by the constitutional officer, the Comptroller and Auditor General and an independent Dáil committee.

Earlier, Social Democrat TD Catherine Murphy said it is hard to have confidence in how NAMA handled the sale of Project Eagle.

Speaking on RTÉ's Morning Ireland, Ms Murphy, who is a member of the Public Accounts Committee, said there were serious deficiencies in how the sale was carried out and a wider investigation into other sales should be carried out.

She said that such a probe should be carried out by a commission of investigation.