National Party Leader Simon Bridges says former health minister Jonathan Coleman was definitely not told of the issues at Middlemore Hospital, and says the blame lies with Counties Manukau DHB.
Mr Bridges, speaking this morning to TVNZ 1's Breakfast, said the mould, leaks and power issues at the south Auckland hospital are "not good enough" and that "the reality is we didn't know".
"It sounds like we should have," he said - "it wasn't brought to the minister's attention."
Counties Manukau DHB knew of the rot inside walls and potentially dangerous mould as early as 2012 in four leaking buildings - Scott Building, the McIndoe Building, Kidz First and the SuperClinic Complex.
A facilities stocktake reported by RNZ has shown a total of 16 hospital buildings considered to be in the high or medium-concern categories.
The issues will likely cost tens or even hundreds of millions of dollars to fix, and Mr Bridges says the current government should "get on with things".
"They could do a PPP (public-private partnership) on something like Middlemore if that's what's required," Mr Bridges said.
"They've got to get on and do it."
Mr Bridges said the blame in this situation would appear to lie with Manukau DHB.
Former facilities manager at CMDHB has told RNZ that the board lacked the funding the maintain the buildings, and that the water, sewage and underground services are outdated.
The CMDHB board made no mention of any of the issues at their first public meeting since news of the issues broke, RNZ reports, and have only issued a statement saying they are "completing a paper which addresses these questions".