Signs are pointing to a slowing of infection rates, Dr Ashley Bloomfield says.

Health Director General Ashley Bloomfield said New Zealand may be seeing its peak of coronavirus cases right now, as new cases flatten off while testing ramps up.

But Bloomfield would like to see several more days with stable or dropping numbers before coming to that conclusion.

There were 82 new confirmed or probable cases of coronavirus as of Saturday morning at 9am, bringing the total to 950.

This increase in cases was broadly in line with recent days, even as testing numbers have ramped up thanks to a new case definition being rolled out to medical profession.

KEVIN STENT/Stuff Dr Ashley Bloomfield said New Zealand may be peaking right now.

More than 3200 tests were completed on Friday - almost twice the daily average the week earlier - but the number of new cases was broadly similar.

"What we have seen over the last four or five days is effectively a flattening-off of the number of new cases, including over the last two or three days with that much higher level of testing" Bloomfield said.

"In fact the test positivity rate has dropped. That's good. That's encouraging."

"It may well be it's [Covid-19] peaking now, because we're seeing it's flattening off."

He would prefer to see several days with dropping numbers of new cases before confidently saying New Zealand had peaked however.

"What we will be really looking for is when the number of new cases each day starts to drop."

"We're increasingly confident that these lockdown measures are working."

The full capacity of 5200 tests a day was still not being used. A slight drop-off of tests was possible.

"People are less likely to go out to seek care over the weekend, but also there might be reduced hours for the [labs]," Bloomfield said.

"We've got more capacity than we need to do testing at the moment and that's very much deliberate."

There were 100,000 nasal and throat swabs in stock currently and enough testing gear for 37,000 tests - with more on the way.

The Ministry of Health's technical advisory group widened the case definition on Friday, saying doctors should test if anyone had respiratory problems that could be linked to Covid-19 - even if they didn't have a fever or a link to travel.

Bloomfield said the ministry were currently looking at the possibility of surveillance testing, which could take the form of random tests within specific communities.

The work for this surveillance testing was still being done however.

This testing would help inform whether or not the country moves out of lockdown at the end of the four week period.

Of the 950 total cases just 1 per cent has been conclusively linked to community transmission, with the majority linked to either overseas travel or a close contact who has travelled overseas.

But another 17 per cent of cases are still under investigation.

Ten people are in hospitals around the country, including one in intensive care in Wellington.

One person has died from coronavirus in New Zealand while 127 people have recovered.