Emails falsely claiming Labor candidate for Eden-Monaro Kristy McBain has pulled out of the race and voters must vote for Liberal Fiona Kotvojs have been referred to a taskforce that includes the Australian Federal Police.
The Eden-Monaro byelection has been plagued by a series of emails that have taken aim at Ms McBain making a number of spurious allegations, including that she had COVID-19.
A new version of the email was detected yesterday that claimed Ms McBain had pulled out of the race due to illness.
It also told recipients they should remove signs advertising for Ms McBain and that their votes wouldn't be valid unless they preferenced Dr Kotvojs before the Labor candidate.
While versions of the email have circulated in recent weeks, it was the false information about the race and voting process itself that prompted the Australian Electoral Commission to act.
While the emails promote the Liberal candidate, the party maintains it has nothing to do with them and condemns the messages in the emails.
It is unclear who is targeted as recipients of the emails, with many people who report receiving them living outside the electorate, and even outside NSW.
The Electoral Integrity Assurance Taskforce was set up for the first time at 2018's "Super Saturday" byelections and includes representatives from the federal police, Home Affairs department and Australian Security Intelligence Organisation.
Labor's national secretary Paul Erickson said the claims in the email were wrong.
"The spread of disinformation online is a threat to democracies across the globe," he said.
"I understand the Australian Federal Police have initiated an investigation into the matter."
The claims that a candidate has withdrawn due to illness and directions to take down signs and preference a Liberal candidate instead have parallels with a similar email campaign aimed at former independent MP Kerryn Phelps in the Wentworth byelection.
Those emails said professor Phelps had pulled out of the race due to HIV.
"It's really important that they are seen as the same MO, they have very similar wording," professor Phelps said, pointing to a vein of homophobia and misogyny in the way the emails were written.
"It's a clear attempt to manipulate the result of an election."
The emails about professor Phelps were referred to NSW Police and the Australian Federal Police, but an investigation that was concluded after polling day found no culprit.
Professor Phelps said it was important that future investigations came out with a result before polling day.