Former prime minister Tony Abbott's sister, Sydney councillor Christine Forster, had her jacket ripped as she tried to enter a fundraiser surrounded by hundreds of Manus Island detention protesters.
Riot police formed a human chain to shield guests arriving for a Liberal Party fundraiser from several hundred Manus Island protesters who had formed outside.
Immigration Minister Peter Dutton and Mr Abbott attended the event.
Cr Forster had to be helped through the crowds by police and had her clothes torn in the crossfire.
The protestors were calling for the Immigration Minster to restore services to the now-closed Manus Island detention centre and bring the remaining asylum seekers to Australia.
The Australian Government had officially closed the detention centre on the Papua New Guinea Island on October 31.
Protesters on loudspeakers harassed and berated guests with police forced to intervene several times.
Hundreds of protesters came with whistles, pots and pans, shouting "Abbott, Dutton, blood on your hands" and "Shame on you" to the guests who made their way through through the crowd.
Activist Lily Campbell said she was protesting because Mr Dutton and Mr Abbott were "responsible for the siege on Manus Island right now".
"I think every refugee should be brought here and should be granted asylum in Australia," she said.
"I can't believe the state it's got to on Manus Island," another protester, Margaret Walters, said.
"It's just atrocious … they should never have been put in an offshore detention camp."
Hundreds of people also marched through central Melbourne earlier tonight calling on the Federal Government to assist refugees at the Manus Island detention centre.
The rally began at the State Library before demonstrators marched along Swanston Street.
There were no arrests.