Australian woman Lucinda Baulch spent 28 days in the Grand Mercure in Wellington, after refusing to get a test.
Baulch, who is a vet nurse, flew to New Zealand to deliver three children to their caregivers in February.
She refused a test, arguing she had not been provided with enough evidence of its safety or effectiveness.
However, it was later revealed that she had protested against Covid-19 protection measures in Australia and she had starred in a series of YouTube videos with a notorious conspiracy theorist during her elongated period in managed isolation.
RNZ made a request under the Official Information Act for details of the costs incurred by New Zealand taxpayers in keeping Baulch in MIQ for 28 days.
In its response, an Ministry of Business, Innovation and Employment (MBIE) official said there was no requirement to charge more if people stayed longer in MIQ.
"Regarding the additional 14 days, there is no provision to charge any additional amount if someone has to stay for longer than the initial 14 days. If, for example, they have contracted Covid-19, or are a close contact of someone with Covid-19, or have refused to be tested for Covid-19".
The MBIE official said they were withholding the details relating to the costs Baulch incurred during her initial 14 days stay due to privacy reasons.
They also withheld general information about the costs of staying at any particular MIQ facility, as it could "prejudice the ministry's ability to carry out commercial negotiations with MIQ facilities".
The official said it was not possible for MBIE to calculate an accurate "cost to the taxpayer" as other agencies involved, such as NZDF, Ministry of Health, and New Zealand Police, were all responsible for their own funding.
However, a Cabinet Paper from July last year estimates the average cost for a single traveller over 14 days in MIQ would be around $7000.
This does not include costs such as transporting people, or MBIE's overheads to operate the MIQ system.
