An Australian anti-vaccination ad has caused an uproar for comparing childhood immunizations to rape.

The ad posted on the Australian Vaccination-skeptics Network Facebook page, before it was deleted, shows the image of a man violently covering a distressed woman's mouth with the blurb: "FORCED PENETRATION: Really — no big deal, if it's just a vaccination needle, and he's a doctor. Do you really 'need' control over your own choices?"

Commenters called the ad "disgusting" and a "new low" for the controversial anti-vaccine group.

An administrator of the Facebook page posted Wednesday morning that the not-for-profit doesn't directly run the Facebook account, despite it containing a link to the group's website.

"This page is open to the public. We sincerely apologise for an earlier post that caused offense to many, including supporters. We are still investigating and have taken your comments on board (sic)," the post read.

The ad was released after the Australian government unveiled last week a new "no jab, no pay" policy, which would cut child benefits to parents who refuse to vaccinate their children.