Ombudsman Emily O'Reilly has named and shamed two Government departments as being the hardest to deal with.
The information commissioner revealed there was a culture within justice and health which made them the worst offenders for not giving out data, while revenue commissioners had "upped their game".
She also argued that the National Asset Management Agency (Nama) should fall under her remit for Freedom of Information requests.
The Information Commissioner told the Oireachtas Joint Committee on Finance, Public Expenditure and Reform that over the last five years Government departments and bodies had cited 230 enactments containing non-disclosure provisions for not handing over information.
She said that while the Department of Justice was afforded certain protection, there was a reluctance for it to allow anyone else to oversee matters, particularly in relation to asylum seekers.
"I think there's a culture in the Department of Justice which goes back to the history of the state and fact that they find it, perhaps, hard to trust a body outside of their own culture," Ms O'Reilly said.
The Ombudsman said there were also issues in relation to getting records from the Department of Health.
"I think there's a culture in that department which stems from pressures it's under, the fact it's continually fighting in so many fights and the fact it's formed in such a particular way," she added, referring to changes in personnel and governance over the health service. It's like trying to grab in to a moving object and it never stands still.
"Justice and health may be the most difficult to deal with, but most departments do their best," she said in reply to questioning from Independent TD Stephen Donnelly.
Elsewhere, Ms O'Reilly also said that while Nama chiefs believe their work is so commercially sensitive and important to the country and confidentiality needs to be ensured, she disagrees and wants the body under her remit.