The Government's Managed Isolation and Quarantine department said it wouldn't comment on an individual case without a privacy waiver but confirmed it could hold people with no signs of Covid in managed isolation up to 28 days if they refused a test.
A second traveller, Guy Davies, was also being kept in managed isolation longer than 14 days for refusing a Covid test, the statement said.
More than 130,000 people have stayed at managed isolation facilities on their return to New Zealand, the vast majority taking Covid-19 tests.
The MIQ system was a cornerstone of New Zealand's Covid-19 response and mandated in law to prevent and limit the risk of an outbreak.
Returnees were required to remain in managed isolation for at least 14 days.
"If a person does not have their final day 12 test, they will be required to stay in isolation or quarantine until they meet the low-risk indicators, up to a maximum of 28 days," MIQ said.
"People refusing their day 12 test are offered a test each day of their extended stay.
"If they agree to a test, return a negative result and meet the standard exit health criteria above, they would be able to leave.
"The maximum time a person who is in a bubble of one and is asymptomatic can be required to remain in an isolation facility under the Quarantine Order is 28 days."
News of Hawkins' hunger strike follows Australian woman Lucinda Baulch's refusal to get a test while staying at the Grand Mercure in Wellington in February.
Baulch's refusal to take a test led to her being kept in isolation for 28 days, with New Zealand taxpayers left to foot the bill for her month-long stay.
The Ministry for Business and Innovation confirmed at the time that anyone who did not have their final day 12 test would be required to stay in isolation or quarantine up to a maximum 28 days until they met "low-risk indicators".
Baulch, who is a vet nurse, flew to New Zealand to deliver three children to their caregivers.
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.