Authorities in Victoria have said a fourth person has tested positive. A woman in her 20s, who is a resident of Melbourne, is recovering at home with the respiratory illness. The confirmation brings the total number of cases in Australia to 10.
On Saturday morning, Mundine, who rarely strays far from controversy, took to Facebook to put forward his theory on the outbreak.
"I don't even think this Coronavirus is real," he wrote on his Team Mundine page.
"I think it's a ploy to give a mass vaccine, look into it."
Many on his social media gave Mundine short shrift, asking what his qualifications were and if he had a Nobel prize.
"I think you are suffering from a corona induced illness due to the stupid things you say sometimes. The virus is real."
"If one has to choose between CSIRO scientists and your ridiculous comment about Coronavirus and vaccines in general it would appear you have lost another fight by KO," said another.
"Come on bro keep it real you do no favours for yourself and your people by issuing such idiotic statements."
But he also has some fans with one person suggesting the virus crisis had been made up to distract from the slow roll out of 5G technology in China.
It's not the first time Mundine has put forward anti-vaccination conspiracy theories.
In 2019, Paralympian Kurt Fearnley labelled Mundine a "peanut" for "promoting fear" after he shared a video airing discredited claims that vaccines can cause autism.
Don’t vaccine your kids period! The government bully you into vaccine ! Do your research on the shit & watched the documentary vaxxed ... https://t.co/PKX6qSYtm5
You can’t make this shit up. We’ve became so comfortable that some promote fear in our peace and others promote apathy in what should be feared... You got many mates with Polio? I do. A heap. From countries that didn’t have the luxury of vaccinations you peanut.... https://t.co/yejUujRfoT
Mundine had urged parents not to vaccinate their children and said the government were bullies.
Mundine then pointed to his Facebook page where he posted a link to a December 2018 video from New York radio show The Breakfast Club where the hosts alleged there was an agenda set by big pharmaceutical companies against African-Americans.
"MRR (Measles) vaccine gives black boys autism at a rate 240 per cent greater than their white counterparts," one of the hosts said.
"It's wiping black boys out, not just with autism — so what the pharmaceutical industry is doing is getting a customer for life."
Mundine's comments were immediately labelled as "dangerous" by others, especially as they come amid in a worldwide measles outbreak that has sparked warnings about the importance of immunisation. He was also heavily ridiculed for the tweet with many punters suggesting he had taken one punch too many.
ANTI-GAY COMMENTS
In 2018, he again courted controversial by suggesting that the death penalty would dioscouarge homosexuality.
"If we were to live in a society, just like in Aboriginal culture, that homosexuality is forbidden and you do it and the consequences are capital punishment or death, you think they are going to do it? Or think twice about it."
This comes after Scott Morrison announced the government's plan to take evacuees from Wuhan to Christmas Island where they would be detained for 14 days.