"Public health experts from the Victorian team, together working with colleagues at a national level, will spend the next day looking through in fine detail, looking for trends to have a really clear sense of exactly what is presenting and exactly what the nature of our challenge is", he said.
Victoria's previous case record was 532 cases reported on Monday.
An alarming number of Victorians who have tested positive for coronavirus are not staying home, with more than 100 referred to police, as the state recorded 627 more cases and another eight deaths.
As greater Melbourne passed the halfway point of a lockdown initially meant to last six weeks, Premier Daniel Andrews said the state would be stuck in "limbo" unless it could cut the infection rate. "And, as the numbers show, the virus does not discriminate".
Additionally people in the Colac-Otway, Greater Geelong, Surf Coast, Moorabool, Golden Plains and Borough of Queenscliffe council areas will no longer be able to visit people or host visitors in their homes. "That's contributing to the significant numbers", he said.
"People are visiting friends and family - and taking the virus home with them".
Just a day after restaurants were banned from serving customers indoors, the decision was reversed following a torrent of online criticism over images of mostly blue-collar workers forced to eat on pavements and in parks - and even inside public toilets to escape a torrential downpour.
"And for so long as that continues, then we will continue to see numbers go up".
Trauer said staff at elderly care facilities might be responsible for the outbreaks there.
Mr Andrews spoke to Prime Minister Scott Morrison about the ongoing outbreak on Thursday night and reportedly discussed the possibility of increased restrictions.
"We've now been in this lockdown (in Melbourne) for some weeks, and we are not getting the results we would hope for, and as a result, the further measures that are taken are certainly necessary", Morrison told reporters in Canberra.
"On some days the virus wins, on other days we beat it".
The country has confirmed a total of 16,298 cases since the pandemic began.
The US counted 1,379 new deaths in the 24 hours before 1.30am Irish time, plus another 72,238 new infections.
Queensland state today said it had found three new cases, two of whom were believed to have contracted Covid-19 while in Sydney, the capital of New South Wales state.