He believed it had the ability to damage New Zealand's faith in the testing system if people were using the tests in a fraudulent way, and it would have a negative effect on businesses that were struggling to continue working during the height of the Omicron wave.
"It's no joke. If you are using some method to defraud your employer by having them support you with a period of sick leave, I would have thought that was criminal behaviour.
"Certainly, it sounds like a form of fraud, at the very least a deception of your employer.
"The other thing that I think is particularly distressing about this sort of behaviour is that we know one of the features of the Omicron wave is that not only does it make people very sick and put them in hospital, it also puts a huge strain on essential services.
"People taking sick leave when they are not sick could make the worker shortage even more intense."
It was the worst time for people to be acting in this way, "Let's hope there is quite a decisive response to this kind of behaviour," he said.
A police spokeswoman said police were unable to comment.
Baker said it was unlikely the Covid-positive tests were fake.
"Basically, the tests are very specific and they are identifying one of the proteins that form the virus.
"It's a chemical reaction and it's designed to home in on the structure of that protein."
University of Otago immunologist James Ussher confirmed the tests themselves would not be able to spread the virus because the testing process made the virus inert.
The person responsible for the Facebook post had not responded to calls for comment.
Supermarket staff moving from desk to distribution
New World head of marketing Pippa Prain said staff were moving from their desk jobs to help in the distribution centre as more and more staff were having to isolate.
"We just roll up our sleeves and muck-in, we are all one big team."
They had also launched a recruitment drive and were looking for more staff to help out in what was a fluctuating situation.
Prain told AM they would not run out of food. The biggest problem was getting food from the distribution centre out to stores and on shelves.
They were prioritising getting the essentials out to stores so people might see a few gaps on the shelves, she said. Some stores may also be changing their opening hours to give teams more time to re-stock the shelves.
RATs were available in store at cost this week, but numbers would be limited per customer.
Current Covid numbers could be 2-3 times more
Epidemiologist Rod Jackson said the numbers being reported were the "minimum numbers only" and the actual number of cases could be two or three times as many.
"It may be coming down, unlikely I think yet. It could be going up. We just don't know. The numbers just don't help any more."
He suggested reporting the figures to the nearest thousand to remind people just how inaccurate they are especially now people were doing them at home.
"In future I think it would be much much better to have it done by people who were trained and then report every case."
A new report about the accuracy of RATs found that 50 per cent of true positives could be missed as it depended on a number of factors including how and when you did the test.
Jackson said New Zealand was at the stage of the pandemic where it had to be as "pragmatic as possible". For the majority of people who were vaccinated, it was not a severe disease for most people.
He suggested reducing the isolating period from 10 to seven.
"It will mean more cases will slip through, but I think that's practical."
The rising hospital rates were worrying especially once it spread more rapidly in older people. "That's the biggest worry, if hospitals get overloaded and sick people just can't get it."
