Financial experts believe the breakthrough will also help better predict when the property market will bottom out.
In a landmark ruling, the Information Commissioner has decided the agency should be subject to information requests under environmental freedom of information.
Freedom of Information campaigners also believe the decision could leave Anglo Irish Bank open to inquiry.
The ruling emerged after Gavin Sheridan, a Dublin-based online journalist, sought information on the body via the 2007 freedom to environmental information statutory instrument.
NAMA refused to supply the information, saying the refusal was justified on the grounds that it is not a public authority within the meaning of the 2007 regulations
However, Information Commissioner Emily O’Reilly found that the national property company was not justified in its action and she annulled the original refusal, saying it was a public authority within the meaning of the regulations.
It is expected that NAMA will attempt to appeal this latest review. It has up to eight weeks within which to do so.
Professor of finance at Trinity College, Brian Lucey, said the decision was important, as it should allow taxpayers to see “what business NAMA are doing, who they are doing it with and for how much”.
One of the basic problems with NAMA, he said, is its opaque nature.
“This opacity has hugely hampered the information discovery in property. We need such information discovery if we are to get to the true state of property and property prices.
“Secondly, NAMA’s opacity has been a huge liability on the public as they have pretended that they could not be transparent and efficient. The responsibility to be transparent cannot be dodged by a public body like NAMA.”