NSW's COVID-19 outbreak crosses state borders, new cases reported in Melbourne

New South Wales' growing COVID-19 outbreak has crossed state borders with new cases and several locations of interest identified in Melbourne.

This comes as NSW recorded 89 new local COVID-19 cases on Tuesday, a decrease from the 112 reported on Monday. Of these, 21 were infectious in the community.

Victoria's COVID-19 Commander Jeroen Weimar has confirmed two members of a family-of-four had tested positive for COVID-19 upon travelling from Sydney to Melbourne on red zone permits.

Three family members had returned to their home in the City of Hume on July 4 by plane and the fourth travelled by car on July 8, The Guardian reported

All members had initially tested negative on arrivals but were retested after becoming symptomatic on Sunday.

Weimar said he was not concerned about transmission on the flight as the cases had initially tested negative.

However, several locations of interest have been identified in Melbourne after two removalists also tested positive.

The Age reported the group of three, from Sydney, had travelled to Melbourne where they completed a drop off in the City of Hume and a pick up in Maribyrnong before driving to South Australia.

Weimar said one of the three removers was contacted by NSW Health on Friday, when in South Australia, and was identified as a primary close contact of another case.

They subsequently tested positive for COVID-19 and are now back in Sydney.

Locations of interest include a Mobil petrol station and McDonald's in the suburb of Ballan, several shopping centres and the Ariele Apartments in Maribyrnong.

Sydney recorded a massive spike in cases with 112 reported on Monday - following 77 new cases reported on Sunday. The current NSW outbreak stands at 678 infections.

Dozens of cases have been hospitalised and almost 20 are in intensive care.

The cases continue to rise despite the city entering its third week of a strict COVID-19 lockdown.