In a statement, the Ministry said today's case is a woman in her 60s who arrived in New Zealand on 30 June from Pakistan via Doha and Sydney.
She has been in managed isolation at the Novotel in Christchurch, and tested negative at her first test around day 3 of her stay, then tested positive around day 12 of her stay in isolation.
The ministry said the case emphasises why people need to be tested twice during their time in managed isolation.
"The second test around day 12 is needed because the infection may take longer to develop in some people, and is one of the checks used to find out if a person can leave managed isolation."
The case brings New Zealand's total number of confirmed cases to 1,195, which is the number reported to the World Health Organisation.
One previously reported case has recovered from COVID-19, so the total number of active cases in New Zealand remains at 25.
There is no-one in New Zealand receiving hospital-level care for COVID-19.
And it has been 74 days since the last case of COVID-19 was acquired locally from an unknown source.
There were 1,620 tests completed yesterday, bringing the total number of tests completed to date to 431,263, the ministry said.