Foreign nationals could be using fraudulent vaccine exemptions to get out of having a jab before entering the country - and there are worries health authorities might not be awake to the problem.
A shonky vaccine exemption was discovered by translator, Diana Renker, just one of the hundreds of documents she had translated in to English over the years for clients, often in support of visa applications.
The document was signed by a German doctor, and as part of the usual checks she did, she punched his name, Michael Foti, in to Google.
"I found out that he and his wife run the medical practice together and they are quite vocal opposing all kinds of vaccinations. They were in the newspaper because they had been issuing mask exemption certificates for local high school students," Renker said.
She did not know what this exemption would be used for, but from November, all non-New Zealand citizens required either a vaccine or an exemption, in order to enter the country.
"The document itself was genuine but I was suspicious of possible intended fraudulent use. So I dug a bit deeper and then I came across the court case in Germany where an identical certificate issued by the same doctor had been declared as not valid."
Renker made a note at the bottom of her signed translation that she had concerns about the veracity of the document, but she worried about how much use this would be.
"If a client isn't happy with the note, they can either try to edit it out of the PDF or they just go to somebody else who may not take the same moral or ethical approach to the issue and is just happy to provide them with a translation."
The head of the agency that gave Renker the translating job, Mark Berghan, said he had come across numerous questionable documents over 19 years working as a translator.
The willingness of New Zealand authorities to accept easily doctored PDF's in digital form, opened the system up to fakes being used, he said.
"We've had birth certificates that have obviously been forged, one where a guy was handwriting stuff on the original birth certificate in front of me, to bank statements where the person has given us a PDF that has been obviously edited postproduction, we've had university degrees."
However, he had given up alerting Immigration New Zealand, having approached them multiple times without a single response.
"If you're aware of crimes being committed, there should be a process that's in place there so that we can report it, because my other big concern of course is that if somebody is using our translations and they're shown to be fraudulent, does that come back on us in any way?"
The president of the New Zealand Society of Translators and Interpreters, Isabelle Poff-Pencole, said as well as a process for the reporting of suspect documents, tighter controls were needed on who could translate them.
"In Europe, for example, the documents must be certified by accredited translators. At the very least, the New Zealand Society of Translators and Interpreters would like for the government to rule only professional translators be used."
On the suspect vaccine exemption, the Ministry of Health said it was aware of the risk of fraud but that its processes for dealing with it were kept "up to date" and in line with "international best practice."
It said showing false documents could result in a $4000 fine and that anybody who suspected fraud was obligated to notify it.
It did not say if it was aware of the exemption signed by the German doctor.
Immigration New Zealand responded by pointing to its website that directed those wanting to report an immigration offence to the independent charity, Crimestoppers.
This involved calling an 0800 number or filling in an online form.