The central health agency is promising changes to how it handles OIA requests after it dealt with one from RNZ unlawfully.
RNZ asked Health New Zealand under the Official Information Act about junior doctors' jobs in April 2023, and got a response a year later. It is meant to take 20 working days.
The Ombudsman investigated, and told RNZ in a letter on Wednesday the final opinion had now been reported to the Health Minister.
The investigation found that when Te Whatu Ora told RNZ in mid-2023 it would respond, it had not done all the work needed to ascertain that, as required.
"There has been a failure to meet the requirements imposed by the OIA," Peter Boshier wrote.
"HNZ's decision was invalid, and was therefore in breach of section 15(1) of the OIA and contrary to law."
After RNZ got the information, it was able to report last month that the cost of junior doctors doing extra hours to plug workforce shortages had skyrocketed to more than $70m a year.
In its OIA response, Health NZ told RNZ it was "very sorry for the delay".
It remains unclear why it took so long.
"Before a decision can be made on a request, an agency should have identified the specific information within scope of the request, collated and reviewed this information, and set out specific criteria for determining which information (if any) is to be withheld," Boshier said.
Health NZ did not do that.
It told the Ombudsman it had made changes as a result, comprising weekly refreshers on OIA law for its OIA team, mandatory training on material from the Ombudsman for OIA advisors, communicating better with those who request OIAs and doing regular quality control testing.
Long delays to OIA requests often require RNZ to make fresh inquiries to determine what has changed in the interim, and if this requires a further OIA, then that holds up the information getting to the public yet again.