Finance Minister Michael Noonan said a review of the sale of a company to businessman Denis O'Brien had concluded that the sale was "managed in the best manner possible" for the State.
Mr Noonan was responding to a written question from Independent TD Catherine Murphy, who had questioned the sale of Siteserv to a company owned by Mr O'Brien.
The utility and infrastructure firm said yesterday that it was "disappointed" that Ms Murphy continued to make "public accusations" about the 2012 sale by the former Anglo Irish Bank to Mr O'Brien.
Mr Noonan told Ms Murphy in his written parliamentary answer that he had ordered a Department of Finance review into the €45m purchase of Siteserv from Anglo successor IBRC.
The deal included a debt write-off from the State-owned bank of more than €100m.
Mr Noonan said the sale "raised concerns about the quality of some of the decisions taken in respect of the transaction".
Among the concerns were the fact that the same law firm, Arthur Cox, had acted for both the buyer and seller.
The Finance Minister said that, "in light of those concerns", he met with members of IBRC's board to discuss the deal.
The board members had provided reassurances in relation to the matters, Mr Noonan added.
"They further assured me that the transaction had been thoroughly assessed by the IBRC board and [it] was managed in the best manner possible to achieve the best result for the State."
Arthur Cox had used so-called Chinese walls to ensure that the deal was fair.
Siteserv said that "any attempt to continually portray the transaction in such a negative manner is completely without foundation and is purely agenda driven".
The company added that there had not been another significantly higher bid for the company.
The sale of the business was "conducted entirely in full compliance with best corporate practice and best corporate governance standards," it added.
This morning, Siteserv chief executive Sean Corkery told Morning Ireland that everything about the sale was above board.
He said selling the company saved 1,600 jobs.
Siteserv was sold to Millington, a company owned by businessman Mr O'Brien.
That sale was assisted by KPMG Corporate Finance and Davy Corporate Finance, overseen by a sub-committee of the Board of the company, and was subject to a vote of Siteserv shareholders, the company said.
"IBRC had a representative on the sub-committee and was advised by PwC Corporate Finance," it said.
"The reason the Millington bid was successful was that it was viewed by the board of Siteserv PLC as the one that was in the best interest of the company and its employees, and by Irish Bank Resolution Corporation Limited (IBRC) as the best outcome for the State."
The company statement also referred to speculation about a second bidder.
"In terms of media comment concerning a competitor, Altrad Group, Siteserv PLC (in liquidation) said at the time of the transaction, that neither its Board or its advisers ever received any formal approach or offer from Altrad prior to accepting the Millington offer and that any claims regarding a proposed formal and executable offer for Siteserv PLC were spurious and vexatious," it said.