Hundreds of homes across Waikato, the Bay of Plenty and the central North Island could've been signed off inappropriately, with Engineering New Zealand saying it's a "case of intentional misrepresentation".
It was revealed on Wednesday engineering designs submitted to various councils were given the all-clear by a member of Engineering New Zealand who is not a qualified professional - instead using more qualified individuals' identities without their permission.
It's being reported hundreds of homes caught up in the investigation are in the Taupō district, but it's feared the issue may have spread wider.
Police and relevant Government departments have also been informed.
Engineering New Zealand CEO Richard Templer told AM on Thursday it's aware of the concerns and it's a case of "intentional misrepresentation".
He said a member of Engineering New Zealand has "misappropriated" the signature and details of chartered professional engineers.
"Chartered professional engineers are very experienced engineers who've had their competency assessed and tested by senior engineers in the field," he told AM.
"They've typically done at least five years of postgraduate work under supervision and so this person has misrepresented on their documents the designs have been checked and approved and signed off by chartered professional engineers."
Currently, it's believed just one person is involved in the scheme, but Templer said it's not known how many chartered professionals engineers the person has forged. He added it looks like a "very small number".
Templer told AM co-host Laura Tupou he understands people will be very concerned about this, which is why Engineering New Zealand, councils, police and the Ministry of Business, Innovation and Employment (MBIE) are working to resolve it as quickly as possible.
He said the forged documents are producer statements and building consents.
"Producer statements are used by councils where someone has undertaken a piece of design on a building or a renovation and it requires engineering checking and approval," he said.
"It needs to be a high of a high standard, that's why it has to be signed off by a chartered professional engineer."
Templer believes the individual could have inspected the properties and then incorrectly signed off on documents both on-site and in an office.
"As you would understand, there is a huge number of documents associated with building and potentially a very large number of buildings that might be impacted," he said.
"So it's taking a significant amount of time for councils to work through and identify which documents have been correctly signed off and which haven't. So they're having to work with builders and designers across this whole area."
When asked if there are buildings out there that could be unsafe but the occupants or owners believe they're safe, Templer told AM it's too early to say.
"The initial examination is showing that some of the designs are not up to standard, but councils have to work with the builders and designers to have a look at what has actually been built, what has actually been constructed, and then they'll have to work through each one of those situations basically on a case by case basis," he explained.
"Obviously, if they find anything is unsafe, they'll want to work with the building owner, builders and designers to resolve the issue as quickly as possible."
Templer said "hundreds" of properties have been affected, but so far, only councils in Waikato, Bay of Plenty and the central North Island have found records that relate to this individual but stressed every council has been checking.
Templer told AM if any Kiwis have concerns about your building or the way it might've been signed off, he urged them to contact their local council.
When asked how this could've happened and if councils were checking if this person was legitimate, Templer said the details of the person were "completely legit".
"The challenge, in this case, is because it's an intentional misrepresentation. When the council would have seen the signature and the details of the engineer, they were completely legit," he said.
"So you can look at our database, we have a database online of engineers, which includes whether they're chartered professional engineers. So if the council had gone and checked, they would've seen that this person was a chartered professional engineer. That's why it's a serious problem."
Watch the full interview with Richard Templer in the video above.
