NAMA is appealing a judgment made against it to the Supreme Court in an effort to keep its affairs away from prying eyes.
The appeal concerns a decision that could force NAMA to deal with public requests for environmental information.
It has major implications for the agency as it attempts to sell off billions of euro worth of property including unfinished developments and landbanks.
It stems from a query first lodged by reporter Gavin Sheridan in 2010, seeking details of any environmental information impact requests NAMA had carried out.
Requests for environmental information are governed by a European directive, which has been transposed into Irish law. This operates separately to the legislation governing Freedom of Information requests.
NAMA refused to release the information on the grounds that it was not a public body.
Mr Sheridan brought this decision to the Commissioner for Environmental Information, who ruled that NAMA fell within the definition of a public body for those purposes.
NAMA appealed to the High Court on a point of law, disputing the Commissioner's interpretation. The High Court upheld the ruling.
NAMA's appeal against this is now due before the Supreme Court at a "for mention hearing" today while a full hearing has been set for April 7.
Stays on Mr Sheridan's requests, pending the outcome, mean he has not yet received any of the information he first asked for in 2010.