The health department on Friday confirmed 49 of the locally acquired cases are linked to known outbreaks, while 25 were self-isolating throughout their infectious period.

It means 30 people were infectious in the community, while six cases are yet to be linked to outbreaks.

Two overseas-acquired cases were also detected in hotel quarantine, taking the total number of infections recorded in the state to 57 for the second day in a row.

It's expected some of the 55 new infections are the result of day-13 testing of some 2000 people who have been self-isolating after coming into contact with a positive case.

Among the new infections is a police officer based at Knox station, in Melbourne's eastern suburbs.

A Victoria Police spokeswoman told AAP the office will be professionally cleaned and police and support staff will be asked not to attend during this time.

"Victoria Police will work closely with the Department of Health as they conduct contact tracing to determine whether anyone else was in close contact with those who tested positive for coronavirus," she said.

AAP understands 12 officers are self-isolating after coming into contact with the infected case.

IN OTHER NEWS

Meanwhile, Goulburn Valley Health has confirmed a positive case has been identified in Shepparton, about 200km north of Melbourne.

The case is currently at home and isolating, with contact tracing underway.

COVID-19 has been detected in wastewater samples in the area since August 10.

It comes as a coronavirus vaccination hub in Melbourne's southeast has been declared an exposure site after a positive case visited to get their jab earlier this week.

See all the exposure sites here.

The case, who did not have symptoms at the time, attended the Frankston Community Vaccination Hub at Bayside Centre on Monday before testing positive on Thursday.

The Peninsula Health-run site has been declared a tier-two exposure site from 11.30am to 12.45pm on Monday, though remains open for those with a vaccination booking.

There are more than 530 exposure sites in Victoria, with a Reject Shop at Moonee Ponds and Coles Broadmeadows added to the list late on Thursday evening.

Melbourne is just over two weeks into its sixth lockdown, which has been extended until at least September 2.

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