Authorities were kept fully informed of the issues and risks with Middlemore Hospital's buildings, the former DHB boss who led the hospital until last year says.
The bill to fix at least six major clinical buildings was last year estimated at $120 million, a third of which would be for recladding.
Expected costs have since risen because of the need to keep patients inside while the buildings are fixed, and the design for doing so is largely untested.
Geraint Martin was Counties Manukau DHB chief executive from 2006 until last year.
"As CEO at Counties Manukau DHB I became aware of the issues associated with two leaky buildings in 2012. These were the Mental Health Unit and the cladding of the Scott building," Mr Martin said.
"At the time these issues were fully disclosed to the Board and the Ministry of Health from whom funding was sought and received.
"As part of this, a business case was prepared for the replacement of the Mental Health Unit and I am pleased to see that project is nearing competition. I also understand that the same is now true for the Scott Building."
Repair work on the Scott building has not yet begun.
The DHB now expects all the repairs at multiple buildings - needed because of water and sewage leaks, seismic vulnerability and asbestos - to take at least five years, and possibly 10.
It was told a limited number of major building firms were able to do the work, and that fewer still would agree to, because of the level of complexity involved in both hospital construction and leak repair.
Hawkins has been close to signing a contract to fix Scott. It originally built it in 2000-2002, and settled the DHB's leaky building claim against it just last year.
RNZ understands Hawkins has capacity to fix only one room at a time, so the repairs could be very slow.
Mr Martin said further investigations found other problems after 2012.
"Throughout these investigations the board were kept fully informed of the issues and potential risks they posed," he said.
"I am confident that throughout the period the health and welfare of patients and staff was not compromised. I am also confident that the appropriate authorities were kept informed of the issues."
He refused to be interviewed by RNZ, instead issuing a statement.
"I have reviewed the request overnight and decided that it would not be appropriate for me to do an interview. Your interview with former District Health Board chair, Lee Mathias, on 23 March covered the issue and the period concerned."
Mr Martin is now Te Papa's chief executive.
RNZ asked its chair Evan Williams what his board knew of Mr Martin's record at Counties Manukau DHB when he was appointed.
The DHB said in an OIA release to RNZ that "sustained under-investment in our facilities" meant its ageing building stock was "no longer fit for purpose".
"The Te Papa Board did the appropriate checks and due diligence before Mr Martin was appointed, and we are comfortable that we had the information we needed to make the decision," Mr Williams said.
"Mr Martin has had a distinguished career working in a very demanding sector, and we value the skills and leadership he is bringing to Te Papa."
Mr Williams also refused to be interviewed, saying "you are pushing in a manner that is not appropriate" and hung up.