Newly released information further tarnishes the government's gold-plated building products approval scheme Codemark.
The review, released under the Official Information Act, of an audit of certificates for aluminium composite panels for high-rises, says an Australian engineer wrote the evaluation reports.
But that engineer - Benjamin Hughes-Brown - told RNZ he had not intended his work to be relied on this way.
Multiple shortcomings had already been identified in the scheme, which issues powerful product approval certificates that councils cannot challenge. Some certificates - as well as one certifying company - have been suspended.
The Ministry of Business, Innovation and Employment is now overhauling Codemark, which it owns but does not run.
It previously questioned the veracity of an audit it ordered into the certificates for aluminium panels related to what helped fuel the Grenfell Tower fire in London last year, but after many months eventually suspended the certificates for virtually all panels in July.
But the review released under the OIA fully backs that audit.
The review says an Australian fire engineer wrote the evaluation reports the certificates were based on, including about the panels' fire resistance.
But it notes a problem: It is an offence under the law if it is not made clear that a person's engineering registration is held in another country - and these certificates don't appear to make clear Mr Hughes-Brown is a chartered engineer in Australia, not here.
"We were not able to identify Benjamin Hughes-Brown as holding a current registration certificate as a CPEng in New Zealand," the reviewer, Wellington fire engineering firm Cognition, said.
This is now being looked into by the industry group Engineering New Zealand.
"We take seriously the protection of the title Chartered Professional Engineer," ENZ said.
"It's important the public aren't misled about an engineer's status."
Mr Hughes-Brown gave RNZ an interview a fortnight ago, but pulled out of a further interview on Friday on the advice of lawyers.
He has, however, said that he only did preliminary reports which should not have been used as a full evaluation report.
In fact, he could not have done a full evaluation report because he did not know the New Zealand Building Code well enough, or what it said about fire, he said.
The company that issued the certificates, Certmark, appeared confused, he said.
He had now referred this matter to his lawyer, having done the same a year or so ago over Certmark using his name on a report, Mr Hughes-Brown said.
Certmark is one of the largest issuers of Codemark certificates in New Zealand, though it is based in Queensland.
Certmark's managing director John Thorpe told RNZ by email that Mr Hughes-Brown was still his company's "primary fire engineer and has been involved in all fire code evaluations for ... New Zealand".
He continued to do work for Certmark, Mr Thorpe said.
But Mr Hughes-Brown said he had not done any work for Certmark for at least 18 months.
John Thorpe said all his company's certifications here were reviewed by a qualified New Zealand Building Code expert approved by both MBIE and the Codemark administrator Jas-anz.
He would not name that expert. "Our NZ fire consultant has declined to be identified to RNZ," Mr Thorpe said, before listing a host of fire engineering qualifications he said the person held.
Codemark scheme administrator Jas-anz was asked by RNZ to name this expert but said it could not do so when Certmark had refused to.
We asked the reviewer, Cognition, what evidence there was of an expert in the New Zealand Building Code having input to the high-rise panel certificates. It referred all queries to the ministry.
The ministry said neither it nor Jas-anz were required to approve such experts, but Jas-anz did audits and "will typically look at who has been involved in the technical decisions for those certificates".
- in some cases the certificates approved the panels' fire resistance even where it was not clear what panels were made of - whether they had combustible or semi-combustible cores;
- approved some on the basis of incomplete fire testing or expired tests;
- approved some according to current fire tests but where it was not clear if the panel itself had actually been tested.
The certificates also typically lacked any back-up evidence to prove the panels complied with a Building Code rule aimed at stopping flames spreading more than 3.5 metres up a high rise.
All the panel certificates remain suspended except one, and this one has just been reissued for an Auckland supplier but minus any claim about the above rule around fire resistance.
The ministry rejected RNZ's request to talk in detail about this case.
It has now embarked on overhauling Codemark, and wanted instead to talk about that.
It had not found evidence of "major building failures" under Codemark, it said, but added the extent of building industry concerns signalled a different approach may be needed.
- all product testing labs are independently certified;
- all certifiers undergo better quality checks;
- products are evaluated against all relevant New Zealand Building Code clauses;
- product certificates include more information about use, specifications and limitations.