The NWT's first positive case was announced on Saturday morning even though health officials knew about it late Friday night.
"After 10 p.m. (on Friday) we found out about the case," said Kami Kandola, chief public health officer during a press conference on Saturday.
The positive result was officially announced late on Saturday morning in a press release from Kandola's office.
Speaking to reporters, Kandola said the time lag was to ensure enough information was ready for the public.
"Without enough information it would elevate panic," she said.
"When we hear about a case of COVID our immediate focus is isolating that individual or people at risk. Last night it was about contacting the individual first. I'm sure people would want to find out they have COVID not from the news but through a polite call (from health authorities).
"The person who has COVID would want to be informed right away and they need to be isolated. That's the most important intervention I can do. Everyone is at risk. Do you want to hear from the news first or from the chief public health officer first?"
The territory's top doctor also apologized for not informing the public earlier that the health risk posed by COVID-19 was high for all of Canada, and not low for the NWT, as the website of the Department of Health and Social Services had stated.
"Last week there was an incredible increase in cases in Canada. Our public site wasn't updated and we apologize. It will be updated now. (This week) we went into much more aggressive action. This concept of the directive of self-isolation is to prevent risk becoming higher in the NWT. That order was out at noon today. That was one of the measures we were doing to keep the risk from getting even higher."