Thousands of Victorians who attended Saturday's Black Lives Matter protest have been slammed for their "selfish" behaviour and accused of setting back the lifting of lockdown restrictions, after an attendee tested positive for Covid-19.

Authorities confirmed this morning a protester was among the state's eight new coronavirus cases.

The man developed symptoms on Sunday following the demonstration, and was diagnosed through routine testing, chief health officer Brett Sutton told reporters this morning.

"They weren't symptomatic at the time," Professor Sutton said.

Advertisement

But, he warned it is possible that the man was infectious at the time he attended the protest, news.com.au reports.

"How infectious someone is, is not clear, but it is known that people can transmit the virus within 24 hours of developing symptoms," he said.

Thousands of protesters who attended Melbourne's Black Lives Matter rally have been slammed for setting back the lifting of lockdown restrictions. Photo / News Corp Australia
Thousands of protesters who attended Melbourne's Black Lives Matter rally have been slammed for setting back the lifting of lockdown restrictions. Photo / News Corp Australia

While Prof Sutton said it was "obviously helpful" that the protester – along with thousands of others – was wearing a mask, "masks are not 100 per cent protection", he said.

"I hope that anyone who has attended that (protest), and indeed across Victoria, who develop symptoms that are compatible with coronavirus really need to isolate themselves, get tested, get that result back and become well before they get out and about again."

He said anyone who was getting tested should wait to receive their result before getting out and about again.

The Department of Health and Human Services (DHHS) will go through the normal process of identifying close contacts, though it's not clear whether the man had downloaded the Australian government's COVIDSafe app.

Many have expressed they're not surprised a protester has become infected, with some warning this will be the first of many.

"Knew it would happen," one person tweeted this morning.

Advertisement

"What an absolute slap in the face for businesses struggling with restrictions."

Clearly missing the entire point of the protests, another Twitter user accused demonstrators of having "no consideration for other lives mattering".

Another accused the protesters of setting "lockdown back for months" – a sentiment echoed by our Prime Minister this morning – while one went so far as to say protesters should be "charged with manslaughter" if the demonstrations on Saturday lead to any coronavirus-related deaths.

Scott Morrison told 3AW's Neil Mitchell this morning there was "no doubt" the federal government would have been easing Covid-19 restrictions sooner if not for last weekend's protests, adding those who protest again this weekend should be charged.

"I really do think they should (be charged)," Mr Morrison said.

"The issues of last weekend were very difficult, but I think people carrying it on now, it's not about that. It's about political people pushing a whole lot of other barrows now, and it puts other lives and livelihoods at risk."

Advertisement

The PM accused protesters of being selfish.

"Millions of quiet Australians have done the right thing and they didn't seem to be that concerned about their health, or their businesses, or their jobs," he said.

"People who would turn up to a rally this weekend would be showing great disrespect to their neighbours. It's a free country and we have our liberties but the price of that liberty is exercising it responsibly."

The Australian Medical Association (AMA) earlier this week urged the thousands who attended rallies in cities and towns around the nation – in a show of solidarity for the US Black Lives Matter movement and to call for an end to Aboriginal deaths in custody – to voluntarily self-isolate for the next fortnight.

"We need to be very clear – we are still very much in the early phase of dealing with Covid-19," AMA President Tony Bartone told reporters on Monday, saying the protests took place "in defiance of the public health warnings" and put the community at risk.

Dr Bartone said as a health professional, he was "extremely worried" about the images he saw of the protests in cities and towns around the nation, because Australians had made huge sacrifices to try to contain the virus.

Advertisement

"The pictures on the weekend really put all of that at risk," he said.

"The game is very much alive and we all need to be vigilant, but especially those who attended the rally."

The organiser of the Black Lives Matter in Sydney, however, rubbished Dr Bartone's self-isolation recommendation, telling The Daily Telegraph plenty of face masks and hand sanitiser were available to demonstrators and "everyone was appropriately distanced".