Parents who have lost custody of their children are fighting to stop them being vaccinated while they are in state care.
Legal Aid is using taxpayer money to fund the court battle, to the dismay of the Victorian government.
One father, currently unable to look after his three young children, wants to ensure they are not vaccinated, telling a Supreme Court judge: "I'm trying to do the best things for our kids".
"There's more chance of getting bitten by a dog or a shark than dying of the measles," he said.
The children have been housed by the Department of Health and Human Services since September.
The case could now drag out as the parents use Legal Aid funds to fight a Children's Court order, a move that has outraged parents and taxpayers.
"It's very important, I wouldn't want my child to go to a kindergarten and catch something from a child that hasn't been immunised," one man told 7 News.
"I think if they're saying its going to be detrimental to their health, then they would need to prove why," one woman said.
Families and Children Minister Jenny Mikakos said: "It obviously does have implications for our department's ability to place children as well as giving them access, like all other children, to childcare opportunities."
But the children's father told the Supreme Court the kids would be at serious risk if they were immunised.
"We are putting something into our kids that we can't control," he said.
The father described to the court his experience of having measles as a child, claiming that he has passed on an immunity to the disease to his own children.
But Minister Mikakos said she took issue with the anti-vaccination movement.
"We don't take our advice from quacks who peddle misinformation about vaccination," he said.