Testing laboratories say they have been inundated with demand for Covid-19 PCR tests much faster than expected, and there is a major backlog in Auckland.
They say testing needs to be targeted for the people who really need it.
Figures released by the Ministry of Health (MOH) yesterday showed a total of 24,351 tests were done in the past day - 29,000 on average in the past week.
Institute of Medical Laboratory Science president Terry Taylor said the labs were being swamped much sooner than expected.
"Predictions of course the other week were that it would take about another week to be inundated and it only took three days, so that probably says it all," he told Morning Report.
"Everyone's very concerned at the moment about just how we're looking because we cannot afford to inundate our diagnostic laboratories, because we've got all our other testing we need to be doing."
One report suggested up to 10 percent of tests were now taking five days or more to be processed.
"That's a real logistical issue and obviously it's outside of the scope of a professional body to probably even wade into the logistics of that - but that is a problem," Taylor said.
"We know today that in the Auckland region any of those community testing stations are almost exclusively doing rapid antigen tests or handing them out, with the PCR testing reserved for those who really need it."
The government last month announced plans for automation and batch testing to help bring standard testing capacity up to 58,000 a day, with surge capacity to be able to do up to 70,000 a day.
However, the high positivity rate was impacting the system, Taylor said.
"We could no longer pool our samples, so we were effectively back to individual testing," he said. "I know it sounds a bit of an oxymoron but our capacity actually drops in those situations."
He acknowledged that the MOH should have expected that, but said what was needed now was to look ahead to phase three of the government's Omicron plan.
"We're left with the situation now... I think we've just got to look at what's happening now and try and get through it.
"As we move into that next phase - and maybe that's gonna come very quickly because the prime minister and the deputy prime minister were making noises yesterday that may happen - that would help to alleviate some of that waiting time and maybe get some of those people back in the workforce.
"The whole idea is to move away form the widespread testing, and target our treatment and our testing and you would've heard that from the medical association as well."
"The thing that would help is that we're just really testing those that clinically and diagnostically need the testing, rather than the widespread surveillance type - it's very difficult to get that message out at the moment ... we've had two years of another message, so we've really changed things up in the last week and it has been very difficult for the public to get a gist of that."