Aucklanders who work in the CBD - are being asked to work from home tomorrow if they can.

Health officials are scrambling to find the source of our latest Covid-19 community case - a woman who works as a shop assistant in the central city.

Employers and Manufacturers Association Brett O'Reilly told Chris Lynch this is understandable because the last thing people want is a change up alert levels.

"Their trying to be as careful as possible before we get to the point where we have to change alert levels, so from that point of view, I commend that." 

He says that this is a refinement of the approach to localise the risk. 

Covid-19 Response Minister Chris Hipkins says those who are unable to stay away from the city should use face coverings.

He says people should also redouble efforts around social distancing and hygiene.

The Government hasn't drawn boundaries to define downtown Auckland - but is asking employers to exercise caution.

Those who live in the city should minimise their movements and contacts.

Hipkins says the situation is different from the last outbreak... when the city went back into alert level 3.

But he's not ruling out a review of alert levels - saying there isn't enough information to make a decision at this stage.