Victoria has recorded four new positive local cases of Covid-19 on Sunday morning, including two in aged care.
Arcare chief executive Colin Singh confirmed the two new cases at the company's Maidstone facility in Melbourne's inner west in a media statement on Sunday morning.
He said one was a 79-year-old resident who lived near the first two residents diagnosed, while the second was an agency nurse who last worked at the facility on Saturday.
All team members who worked at Arcare Maidstone on Saturday will be required to get tested immediately and isolate for 14 days.
Victorian deputy chief health officer Allen Cheng said the department was aware of the two cases but hadn't been fully briefed on the details yet.
The new cases take the number of active local cases in the state's latest outbreak to 72, with two others recovered.
Health officials are still seeking to pinpoint the source of several mystery cases, with concerns surrounding the highly infectious Delta strain remaining.
Victoria recorded five new locally acquired cases in total on Saturday, with three close contacts of existing cases.
The state's list of exposure sites has swelled to almost 400 overnight after a Woolies, Coles and city office building were added.
Covid fragments were also found in wastewater samples from Melbourne's inner west and north catchment area, a detection described "of interest" to health authorities.
The suburbs have no confirmed cases of coronavirus but it is near the West Melbourne Delta strain mystery cluster.
"The unexpected detections may be due to someone who has had Covid-19 that is no longer infectious continuing to shed the virus or it may be due to an active but undiagnosed infectious case," the health department said.