Regional Public Health were interviewing him further about his travel history.
The man was staying at the Sebel Manukau and tested negative on around day three of his stay. He then tested positive on around day 12 and was being transferred to a quarantine facility in Auckland, the Ministry of Health said.
"This case reinforces why we test people twice during their time in managed isolation," the ministry said in a statement.
"A second test around day 12 is needed because the infection may take longer to develop in some people. It's an important check used to find out if a person is safe to leave managed isolation."
Today, Minister Megan Woods and Air Commodore Darryn Webb fronted media after a family of five escaped managed isolation in Hamilton yesterday.
The mum and four children escaped from the Distinction Hamilton hotel last night and had earlier applied to attend a relative's funeral in Auckland this afternoon. They had arrived in New Zealand from Australia on July 21.
They escaped by allegedly breaking a window off its latches and climbing a six-foot security fence.
The family comprised of a mother and four children aged 12, 16, 17, and 18 years old.
The group had applied for compassionate leave but it was declined. An updated application was "looking positive", Webb said.
"While we can understand their grief we can not let one tragedy to turn into a tragedy of hundreds," Woods said.
Webb said the family was told their application was "looking positive" last night and that a decision would be made by 8pm.
Webb confirmed the family would have been given an exemption to go and view the body of the deceased relative, and then would be taken back to isolation.
At 6:58pm yesterday, before the final decision had been made, people were seen climbing over the perimeter fence of the Distinction Hotel.
An NZDF staffer and a police officer gave chase.
Four members of the family were apprehended by police in a nearby park. The fifth, a 17-year-old, made it all the way to Auckland before being detained. Four members of the family are facing charges of breaching a Health Act notice.