A report by the Comptroller and Auditor General (C&AG) into the sale by Nama of its Northern Ireland properties has found "shortcomings" and "irregularities" in the process, The Irish Times has learnt.

These failings could have resulted in “hundreds of millions of euros” not being realised from the Project Eagle sale, the report is understood to have found.

The C&AG report, which has been given to Minister for Finance Michael Noonan and is due to be published before the end of the month, was requested after allegations that a Belfast businessman, who had been advising Nama, had also been working for a US company that was seeking to buy the agency's Northern Irish property portfolio.

An investigation by British police is already under way into the sale, and a number of arrests have been made.

It is understood that the report finds that while it is impossible to be definitive, shortcomings in the sale process, known as Project Eagle, meant that the agency did not receive hundreds of millions of euros that it otherwise might have.

A spokesman for Nama declined to comment, saying that the agency would respond comprehensively to the report when it was published.

Hypothetical

However, it is understood that Nama and other parties have been circulated with drafts of the report and that the agency is likely to strongly contest its findings.

For a State body to reject the findings of a report by the C&AG, which operates as the State’s own financial watchdog, would be highly unusual.

A spokesman for the Department of Finance said that Mr Noonan would brief his Cabinet colleagues over the coming weeks in advance of the publication of the report, and he would not be commenting before that.

However, a source pointed out that “any assessment of achievable values is hypothetical. It is always hypothetical”.

The sale by Nama of the Northern Ireland properties to US firm Cerberus for €1.6 billion in 2014 has been the source of enormous controversy.

Independent TD Mick Wallace, who has been highly critical of the agency, told the Dáil that politicians and business people in the North were to benefit from the deal.

The forthcoming C&AG report is likely to add momentum to calls for a commission of inquiry into the Project Eagle sale and The Irish Times understands that officials have already begun to explore what form such an inquiry might take.

The Government has consistently resisted calls for such an inquiry, but political sources conceded last night that it may become inevitable.

The controversy comes as Nama’s financial outlook continues to improve.

The agency says it will return a €2.3 billion profit to the State, though in a note to investors earlier this week, stockbrokers Davy said that figure was likely to increase.

The agency was also praised on Thursday by a European Commission report on the performance of the bad banks in Ireland, Spain and Germany. It found Nama has been "very effective with the sale of assets".