Daniel Pettigrew says his practice has been waiting a week to get supplies of Rapid Antigen Tests (RATs) and does not know when they will arrive.
In the meantime, he has had to tell patients to go elsewhere.
The delays were just the latest in a string of logistical hiccups throughout the pandemic, Pettigrew said.
"Through the pandemic we've had issues with PPE, we've had issues with vaccinations, whether they're Covid vaccinations or that first year we had issues with flu vaccine rollout and a lot of it was just logistics of getting these items into the hands of general practices."
Pettigrew acknowledged Omicron had spread through the country earlier than expected, but said it was frustrating being unable to fully look after his patients.
Health services have reported high demand from people wanting the tests, and the Ministry of Health dispatched 5.2 million RATs in the last week.
Covid-19 Response Minister Chris Hipkins told Morning Report supply of RATs depended on how heavy the demand was in each region.
"The systems are bedding in now, so they're getting people through those pick-up points quicker so I think you'll see the system operating more efficiently."
College of General Practitioners medical director Dr Bryan Betty said the demand was not unexpected because the latest variant was spreading rapidly throughout the country.
General practices, Covid-19 testing stations, and pharmacies were being flooded with calls, he said.
However, there had been delays delivering the tests to health services.
"The supply chain for getting the rapid antigen tests out to general practice, pharmacies and, later in the week, supermarkets, is really just getting up and running.
"There's a bit of a lag getting all the RAT tests out to appropriate points of access."
However, the government had promised there were enough tests in the country, he said.
He expected the supply problems would be resolved by next week.
Minister not satisfied with info on PCR testing capacity
Thousands of people still waiting on Covid-19 PCR test results from five or more days ago are being advised to go get a RAT instead.
The Ministry of Health is under pressure for overestimating how many Covid-19 PCR tests labs could process, and now there is a backlog of 32,000 tests that are at least five days old.
The National Party is accusing the Ministry of Health of misleading the public - and possibly ministers - in overestimating testing capacity.
Hipkins told Morning Report he was not satisfied with the information he was given about PCR testing capacity.
"Ultimately, what we've got to do is focus on two things, making sure that we're getting the testing operating smoothly now and making sure that that backlog of testing results gets cleared.
"It's clear that the unpooled sample capacity would be appear to be lower than the information we were given."
Pooled sampling - where a group of samples are processed together and if one is positive then they are unpacked individually - worked well when there were fewer cases, he said.
"On the other hand, when you're getting positive samples in almost all of your pools, than actually that pooling sampling method doesn't work anymore, it's no longer efficient, and so they moved to processing every sample one at a time, and it's clear their capacity to do that was lower than what they anticipated."
Hipkins said he would be seeking answers on the issue.
