Several businesses visited by the Northland's Covid community case weren't contacted by health officials before finding out the news.

One business owner stayed up late into the night hoping to hear from the Ministry of Health but wasn't called until this morning.

Nearly 30 businesses have scrambled to clean and make their workplaces safe after being visited by the community case, a 56-year-old woman who lives south of Whangārei.

The woman had visited places in Whangārei, Ruakaka, Parua Bay, Mangawhai Heads and Helensville (which is in the wider northwest Auckland region).

Yesterday officials deemed they needed to alert business owners first, rather than immediately publicising all the locations the woman had visited.

Director general of health Dr Ashley Bloomfield said there was an obligation to do so.

But the Ministry published the full list of places the woman visited at about 9pm yesterday before all the business owners could be reached.

Just before 9am today, Bream Bay Butchers Ruakaka owner Steve Boobyer said the Ministry of Health had not called them about the situation.

Instead, he found out on a popular local Facebook page.

"We couldn't believe it. Disappointed you know. I think here we go again.

"So shop is shut. We are currently in line at the Kamo testing station waiting for our test."

The store undergos a deep clean every night but will be closed until further notice.

"We know what we need to do."

The Maungaturoto Second Hand shop's owner Nicole told Newstalk ZB she only found out the case had visited when she looked online last night.

She said she tried to contact Healthline, the Ministry, the Northland DHB.

A public health nurse had only got back to her roughly just after 10am today and apologised for not contacting the shop.

"I stayed up really late last night hoping to get a phone call," she told Newstalk ZB.

"I was hoping to start out Monday knowing what to do and I didn't know if anybody else had opened or what.... there's only 30 businesses to call."

She said she had closed the shop this morning and told staff who were working on the day the woman visited to get a test and isolate as well.

The nurse had told Nicole the store could open and didn't need a deep clean but she still wasn't sure how to proceed.

"I'm a little bit angry that I'm not getting supported as to what we need to do as a business."

Last night South Head General Store posted on Facebook they had not been alerted by health officials despite being listed on the offical website as one of the locations.

"We have not been contacted by the Ministry of Health as yet," the post read.

The post urged their customers to self isolate while they tried to get more information.

The South Head General Store had themselves found out via Facebook and the owner had still not heard from the Ministry of Health at 8am today.

Joseph Taylor Homewares also still had not heard from the Ministry of Health at 8.30am today. The Mangawhai Heads Rd store is closed today.

Act Party leader David Seymour said yesterday the Government's delay in revealing the 30 locations the woman had visited was "reckless and risks making a dangerous situation much worse".

"How can people self-isolate and get tested in a timely manner if the Government won't tell them they've been somewhere they may have contracted the virus?

"People want to take personal responsibility at times like this but the Government needs to be transparent and treat them like adults."