One of the cases travelled to Auckland to provide childcare and the other, from the same household, is a truck driver.
The person worked for four days during their infectious period and the company they work for is assisting with tracking their whereabouts during those days, director general of health Ashley Bloomfield said.
"Initial information indicates the person was completing deliveries around the Christchurch area, with some trips to north Canterbury."
The person who travelled to Auckland had a negative test before travelling north and a second negative test before returning to Christchurch on October 15.
The case was not considered infectious when they travelled back to Christchurch.
Both people became unwell last week, were tested on October 26 and both returned positive test results last night.
Both cases are currently isolating at home with public health oversight and plans are under way to transfer them to a local quarantine facility, Bloomfield said.
"The local public health unit is gathering further information from the cases to identify close contacts and exposure events, including any locations of interest."
Hipkins said the Government had always been clear there was no way to guarantee that cases would not come up in other regions.
Christchurch wastewater testing had not picked up Covid-19 - there would be wider testing now done.
People across Canterbury are being urged to closely monitor the Ministry of Health locations of interest website.
A ministry spokesperson said locations may be released for Christchurch at 2pm.
Bloomfield said people in Canterbury – especially those who live in Christchurch – with any symptoms, no matter how mild, are asked to get tested.
