Former Northern Ireland first minister Peter Robinson "flatly contradicts" evidence given by Martin McGuinness on the sale of Project Eagle, TDs have been told.
His claims about the sale of Nama's Northern Ireland loan book come in correspondence that he sent to the Public Accounts Committee (PAC) declining its invitation to appear.
Mr Robinson enclosed his previous testimony to a Stormont committee with his letter, which PAC chairman Seán Fleming said "flatly contradicts" statements made by the Sinn Féin deputy first minister.
Mr McGuinness told the PAC last week that there had been a "determined effort" by Mr Robinson's party, the DUP, to prevent him getting access to information about Project Eagle.
In his testimony to the committee in Northern Ireland last year, Mr Robinson said he didn't want to give the impression that Mr McGuinness had "deliberately lied", but felt it was his duty "to set out the factual position".
However, he also insisted: "The deputy first minister was kept informed of developments in relation to the sale of Nama's Northern Ireland portfolio throughout the process."
At the PAC, Mr Fleming said TDs would have to "adjudicate" on the competing versions of events when drafting their own report.
Mr McGuinness's Sinn Féin colleague, PAC member Mary Lou McDonald, pointed out that Mr Robinson "has the opportunity to come to the committee to have his evidence tested".
She made the distinction that Mr McGuinness had taken that opportunity.
Independent TD Catherine Connolly said she was "disappointed" that Mr Robinson had declined the PAC's invitation.
She said the committee had been placed in a "difficult position" given that he "absolutely contradicts - practically on every point" Mr McGuinness's version of events. Mr Fleming agreed this was "a complication".
In his letter, Mr Robinson said there were "constitutional reasons" why ministers would not wish to "become or appear answerable to a Parliamentary Committee outside of their own jurisdiction".
He said this was further complicated by the investigation of Project Eagle by the UK's National Crime Agency.
Mr Robinson forwarded his previous evidence to the committee in the North and told TDs that if they wanted his view on specific issues they could send him queries by email and he would "provide a response".
The PAC is probing Project Eagle after the Comptroller and Auditor General (C&AG) found that a probable loss of £190m (€223m) was incurred in the 2014 deal.
Nama has rejected this finding. Its chief executive, Brendan McDonagh, defended the €1.6bn sale, insisting it was "not plausible" to say the agency set the reserve price too low.
He said if this was the case, "international investors" that were part of the bidding process would have effectively left "easy money on the table" when they decided not to buy Nama's Northern Ireland loan book.
He said it would be "more realistic" to suggest that the £1.3bn price set by Nama "was a commercially reasonable target in early 2014".
The C&AG, Seamus McCarthy, meanwhile, reiterated that he stands by the report, in what is likely to be the last public meeting of the PAC on the matter before it drafts its own report.
Republic of Ireland
The international firm that advised NAMA on the sale of its Northern Ireland loan book was treated like an “eejit” and a “patsy” prior to the €1.6 billion property transaction, the Public Accounts Committee (PAC) has heard.