COVID-19: Mystery cases don't 'necessarily' mean Auckland can't move down alert levels - Grant Robertson

Just because there are a few COVID-19 cases yet to be linked to New Zealand's current outbreak doesn't definitively mean Auckland can't shift down alert levels, Deputy Prime Minister Grant Robertson says.

Auckland is bracing for an alert level announcement on Monday nearly a month after entering the most stringent restrictions.

But experts have warned of the danger of easing the COVID-19 lockdown in Auckland too soon - with mystery cases throwing a spanner in the works. 

As of Sunday, 34 of the outbreak's 922 cases had yet to be epidemiologically linked to the existing cluster.

"We don't really know what's out there now - we're in a terrible situation where if the virus is just two or three steps ahead contact tracers… it's very hard with this Delta variant to keep up," Malaghan Institute immunologist Professor Graham Le Gros told Newshub.  "We face some pretty terrible times ahead if the virus gets going," 

Robertson was asked on The AM Show if the Government will keep Auckland at alert level 4 while there are still mystery cases.

"Not necessarily," he told host Ryan Bridge. "We look very closely at each of these individual mystery cases... [those] eight [mystery cases] will have reduced down significantly just overnight, I guarantee it, because during the day yesterday there would've been conversations with those people, connections would've been made to other parts of the outbreak and they're no longer considered mystery cases."

Robertson reiterated comments made by Director-General of Health Ashley Bloomfield on Sunday that there was no widespread community transmission in Auckland. 

"We don't have widespread community transmission," Robertson said. 

"Level 4 is tough for everyone - but we know it gives us the best chance at getting on top of the virus and breaking chains of transmission - that is happening but there are still a few cases at the edges."

An update on alert level settings for greater New Zealand, which is at alert level 2, and Auckland will be made on Monday and announced during a press conference at 4pm.