Victoria has recorded its first case of the Omicron COVID-19 variant.
The health department on Wednesday said genomic testing confirmed a traveller who arrived from the Netherlands via Abu Dhabi on Friday has the variant.
They are in hotel quarantine and all other passengers on the flight are being followed up to ensure they have been tested, in line with current requirements for overseas arrivals.
The department is also investigating likely Omicron cases detected in the cities of Casey and Brimbank.
The two cases have returned results with S gene dropout - a signature of the Omicron variant.
"Household contacts of these cases have also tested positive and whole genome sequencing is underway to confirm whether these represent the Omicron variant," the department said.
"None of these cases are linked to international travel and their source of acquisition is under investigation."
Several contacts of the two cases have been identified and instructed to quarantine for 14 days.
Other people of lower risk have been instructed to get a test and isolate until they receive a negative result.
Further contact tracing work is ongoing and is likely to produce more contacts.
It comes as Victoria reported 1312 new COVID-19 infections and a further five deaths.
There are 11,331 active cases in the state, down from 13,050 on Tuesday, including 303 patients in hospital, 97 of whom are in intensive care and 27 requiring ventilation.
The seven-day hospitalisation average sits at 297.
Testers processed 79,490 results on Tuesday, while 3858 people were vaccinated in state-run hubs.
More than 91 per cent of Victorians over 12 are fully vaccinated.
Meanwhile, the Victorian government has announced it will pour $21 million to establish a mRNA research program as part of its push to use the technology to manufacture vaccines on an industrial scale for future pandemics.
