Covid 19 coronavirus: Australia's youngest victim among Victoria's 14 new deaths

Victoria has confirmed Australia's youngest virus death, a man in his 20s, who was among today's fatality count.

Victoria has confirmed 372 new infections and 14 deaths linked to the disease – an increase from the 287 new cases and eight deaths registered yesterday.

Also among the deaths were three women and two men in their 80s, and four men and four women in their 90s.

51 new cases have an unknown origin in Victoria

Victoria Premier Daniel Andrews said there were 51 new cases with an unknown origin.

"There are 3119 cases with an unknown source – mystery cases," he said. "That's 51 that have been added – 51 that have been confirmed as an unknown, a mystery case, since yesterday's report."

Victorian Premier Daniel Andrews speaks to the media during a daily briefing. Photo / Getty Images

Expanding on this, Victorian CMO Professor Brett Sutton said one in five cases was a "mystery case".

"One in five cases we can't determine [the source of the infection]. They don't have anyone in their household, who has been unwell, nobody in the workplace.

"The places they nominate don't have existing cases, clusters, outbreaks so we can't determine absolutely where they got it from but we know there are other opportunities where people can pick it up.

"Sometimes they won't recall a close contact and sometimes they've had a more casual contact and for those people, they can't identify where they've been all with whom, but they will be picked it up there."

Prof says Victoria's cases have peaked

Professor Brett Sutton said he believes Victoria's cases have peaked and are now on a decline.

"We've turned the corner ... and should see a further driving down to transmission with stage four restrictions so it is going on the right direction and I'm confident we've seen the peak but it's got to come down quickly," he said.

Asked when he thinks the death rate might start to come down, Sutton said: "Because we've seen stabilisation in the number of cases, it's essentially levelled off. I think we will see a levelling off of hospitalisations for community cases in the next couple of weeks and the same for deaths.

"If we can drive numbers down from here on in, knowing what we know ... we should see a stabilisation of deaths in the next couple of weeks.

"We are concerned about the significant number of aged-care cases. They are most at risk. Most at risk of dying. We also have to drive those numbers down as well."