MARTIN McGuinness has said he believes there was "wrong-doing" behind Nama's £1.24 billion sale of its northern loanbook.
The Deputy First Minister told a parliamentary committee in Dublin yesterday: "There is a police investigation; they are investigating wrong-doing. Do I believe there was wrong-doing? Yes, I do".
Mr McGuinness accused former first minister Peter Robinson of excluding him from meetings leading up to the deal and challenged the former DUP leader to appear before the committee.
"I have done it, and I think anyone who is asked to come should come," he told the Oireachtas Public Accounts Committee, which is probing the sale.
Earlier this week, Mr Robinson said he had not received an invite sent more than a month ago, adding that he was not answerable to Dublin but would like to be helpful.
The committee said it has couriered a fresh invite to his home, which has been acknowledged.
Mr McGuinness said his only involvement with the Project Eagle sale was in a conference call, along with Mr Robinson, in January 2014 during which the Republic's Finance Minister Michael Noonan said the portfolio was going on the open market.
It was sold to US investment fund Cerberus that April.
Another US company, Pimco, has told the committee it pulled out of an earlier bid after it was asked for a fixer payment of £16 million.
The money was to be shared equally by Belfast businessman and former Nama adviser Frank Cushnahan, US law firm Brown Rudnick, and Ian Coulter, a managing partner of Belfast law firm Tughans, Pimco said.
Mr McGuinness said Mr Robinson told him about the Pimco withdrawal but did not explain further. Neither Nama nor Mr Noonan informed him, he told the hearing.
Asked about Mr Robinson and Mr Cushnahan's relationship, Mr McGuinness said they "were very, very close".
WATCH: Nama explained
Brown Rudnick also acted as advisers in the deal with Cerberus, which has been dogged by scandal after £7 million linked to it was found in an Isle of Man bank account.
All parties have denied any wrong-doing.
Mr McGuinness said both Mr Robinson and then finance minister Sammy Wilson "kept very closely to themselves" about their dealings with parties involved in the sale.
He said Mr Robinson and other members of the DUP had met Pimco and Cerberus without his knowledge.
When he started to suspect that a "deliberate attempt" was being made to exclude him, Mr McGuinness said he did not ask Mr Robinson about it because relations between the pair were fraught after plans for the redevelopment of the Maze site were scuppered by the DUP.
"I am very strongly of the view that I would not have got the sort of answer I would have required," he said, adding that he had come under pressure to collapse the power-sharing institutions at the time.
He added that an investigation by the UK's National Crime Agency, which has so far interviewed more than 40 people, "is taking far too long".
Mr McGuinness said he was not one of the 40.
