A leaflet that labels Yan Yean state MP Danielle Green a supporter of abortion up to birth was distributed in parts of the electorate last week.
Among other claims, the anonymous leaflet says Ms Green supports abortion for reasons such as gender selection.
The flyer shows the crest of the Parliament of Victoria and a photo of Ms Green, the shadow minister for women, who is pro-choice and believes abortion is a decision to be made between a woman and her doctor.
Ms Green said the leaflet was “revolting” and designed to influence the outcome of November’s state election.
“I think it’s the Liberal Party’s dirty tricks,” she said. “It’s really over the top.”
But the Liberal Party’s candidate for Yan Yean, Sam Ozturk, cautioned Ms Green from pointing the finger.
“I’m not involved in that kind of rubbish,” he said.
“While it’s a democratic country, we all have to play within the rules.”
A spokeswoman from anti-abortion MP Bernie Finn’s office flatly denied he had any involvement.
The Labor Party has lodged a formal complaint with the Victorian Electoral Commission on behalf of Ms Green.
The president of the Legislative Council, Bruce Atkinson, and Speaker Christine Fyffe have also called for an investigation into the flyer and its use of the parliamentary crest.
The crest can only be used for official parliamentary business and cannot be used by any other party or organisation to indicate an affiliation with the Parliament of Victoria.
“The leaflet distributed in Yan Yean is in breach of the rules,” Mr Atkinson and Ms Fyffe said in a statement.
“It contains no authorisation and no indication of who is responsible for its production and distribution.”
The VEC now has two investigations under way concerning the seat of Yan Yean, one of the most marginal electorates in the state.
A few weeks ago Mr Ozturk’s office mistakenly sent out thousands of letters that referred to himself as the local Member of Parliament.