Tighter retail restrictions imposed on Tasmania's north-west after a coronavirus outbreak will be lifted on Sunday night, with the situation "largely under control", Premier Peter Gutwein says, as the state records a day free of new cases.

An investigation into a coronavirus cluster in north-west Tasmania finds some staff worked in local hospitals for several days while experiencing symptoms, but the Premier stresses no-one is to blame.

A female healthcare worker "in her 20s" is the latest case of coronavirus confirmed in Tasmania, on the day Australia's Chief Medical Officer apologises for alleging an "illegal dinner party" contributed to the state's outbreak.

Small businesses in Tasmania struggling to survive amid the coronavirus crisis call for clearer messaging from authorities, saying there is no point trading if customers are too nervous to leave home.

The Ruby Princess has been described as the 'ground zero' for a deadly coronavirus outbreak that has taken hold in northwest Tasmania.

Some of Australia's coronavirus restrictions will be lifted earlier than expected with state and federal leaders set to make an announcement next Friday.