Victorian Chief Health Officer Brett Sutton said the increase in cases on Monday was concerning but big numbers could be turned around if people "do the right thing".

"What we're seeing is transmission across settings because people are still going out with symptoms," he said.

"Whether or not it needs a legal direction is a conversation to be had over the next few days, we are not there yet.

"But the solution is there already, which is people not having unnecessary contacts across multiple households, across multiple settings."

Claiming the state's contact tracing detectives had found greater links between households that had been seen as separate outbreaks, Professor Sutton also sent a stern message to younger people.

"No one wants to be in a position where you're killing a family member because you're not looking after yourself in terms of the risk of transmission," he said.

"They can't dismiss it on the basis that they might have a milder illness."

Victoria's 75 new coronavirus cases mark the biggest increase since the peak in late March that put the state into lockdown.

Victoria had its worst result on March 28, when 111 tests returned positive results.

Tough stage three restrictions allowing Victorians to leave the house only for essential purchases were imposed on March 30.

Victoria has had double-digit increases for 13 days in a row - in stark contrast to the rest of Australia.

In the fortnight from June 15 to Monday, Victoria had 367 new cases, while the rest of the country had 65 combined.

In that period, Victoria's active cases have soared from 52 to 288.

Opposition leader Michael O'Brien said Victoria was "the coronavirus capital of the country", and urged the government to take urgent action to avoid another lockdown.

Authorities are yet to decide whether tighter measures on coronavirus hotspots should be imposed.

"We are obviously concerned by the increasing number and upward trend, and we are monitoring the situation very closely," Health Minister Jenny Mikakos said.

"Many of the cases that have come through today, they are overwhelmingly concentrated in those priority suburbs."

More than 792,000 tests have been done in the state, about 53,000 in a blitz on suburbs considered the latest coronavirus hotspots with more than 15,000 completed since Sunday.

Professor Sutton said a call on new restrictions would have to be proportionate.

"We know what the consequences are of a lockdown in terms of fatigue in people's behaviours and we don't want to drive people out of suburban areas into new unaffected areas," he said.

"It's a real challenge for people in their homes if that's what's required, but it's absolutely an option ... and we'll use it if it's required."

One new case was linked to hotel quarantine and 14 are linked to known outbreaks.

Another 37 cases were detected through routine testing and 23 are still under investigation, with both groups possibly linked to known outbreaks.

An Ambulance Victoria paramedic has tested positive for coronavirus. It is the second time a paramedic has tested positive and in both cases, neither case was acquired on the job.

Australian Associated Press