The origin of derogatory online comments about Muslims, purportedly made by a federal Liberal candidate, is now under police investigation.
The candidate for the Tasmanian seat of Lyons, Jessica Whelan, has denied she made the Facebook posts bearing her name.
But Labor seized on the "extraordinarily racist comments" and called for Prime Minister Scott Morrison to step in and sack her.
The Hobart Mercury provided the Liberal Party with two comments purportedly made by Ms Whelan about Muslims on social media, one which says women who supported Islam should be mutilated and sold as slaves.
Mr Morrison said they appeared to have been doctored and Ms Whelan had referred the matter to the Australian Federal Police.
"I don't think it's hard to believe in this day and age that images can be doctored," he told reporters in northern Tasmania on Thursday.
"All we can do, all Jessica can do, is refer the matter to the AFP and have confidence in their ability to pursue the matter in the way you'd expect the AFP to."
His comments came after he and Ms Whelan appeared at an hour-long photo opportunity at agricultural show Agfest.
The candidate had a brief meeting with the leader but when the prime minister went for a walk through the festival to meet voters, his media advisers used themselves as human shields to make sure journalists couldn't stop her.
In a final chaotic dash to a car, Ms Whelan refused to answer questions about her online comments.
Mr Morrison later told reporters she didn't answer any questions because they weren't doing a press conference at Agfest, and that she wasn't beside him facing up to scrutiny because his press conference was being held in the neighbouring seat of Bass.
Deputy Labor leader Tanya Plibersek, also in northern Tasmania, said Mr Morrison had to act, especially after the Liberal Party had disendorsed its candidate for Victorian seat of Isaacs, Jeremy Hearn, for similar anti-Muslim slurs.
"Racism is racism is racism," she told reporters.
"When you've got two candidate saying very similar things, I think it's absolutely vital that the prime minister shows some leadership."
Ms Whelan is the latest of a string of candidates at the federal election to be in hot water over online posts.
On Wednesday, two Liberal candidates were dumped over such posts - Mr Hearn for an anti-Islam rant, and Peter Killin for homophobic remarks.
Labor has also been hit, with Senate candidate Wayne Kurnoth sacked after sharing anti-Semitic remarks, while Luke Creasey kept his place after apologising for posting a rape joke and pornography on Facebook in 2012.
Ms Plibersek ignored questions about Mr Creasey after speaking to reporters about Ms Whelan.
