There are three new cases of Covid-19 in managed isolation today.

The first imported case arrived from the UK via Singapore on October 9 and is in managed quarantine in Christchurch. They tested positive as part of routine testing around day three.

The second and third imported cases arrived from the United Arab Emirates on October 13 and are today being transferred from managed isolation to Auckland's quarantine facility. They tested positive as part of routine testing around day three.

Nine people recovered overnight which means New Zealand's total number of active cases is 40 – all of which are imported cases.

Yesterday New Zealand laboratories processed 4,794 tests, bringing the total number of tests completed to date to 1,026,725.

There were four new Covid-19 cases in managed isolation yesterday and a historical case that was being investigated.

The Ministry of Health said it had been investigating the historical case since yesterday morning after the person returned a "weak positive result".

This individual is a recent returnee from the United States and completed their full 14 days in a managed isolation (MIQ) facility in September.

"They were asymptomatic during their time in MIQ and returned two negative tests during this time. They were released from MIQ on September 21," the ministry initially said.

"After becoming unwell this week, they sought medical care. They were subsequently tested for Covid-19, which has returned a weak positive result, indicating an old infection. We have undertaken further testing today to fully confirm this is a historic infection," the ministry said.

"We are taking precautionary measures as we always do in these instances and the individual has been transferred to an MIQ facility in Wellington. As we have seen with other cases, individuals can return weak positive tests if they have been infected earlier in the year. This case follows a typical pattern of what we have seen in other historical cases.
These cases can emerge after the person has a respiratory illness that is not Covid-19 such as a cold or influenza," the ministry said.

The ministry later said the test result had been confirmed as being a historical infection and the person was, therefore, no risk to the public.