9.25AM: Allegedly false voter enrolments in a key seat in last year’s federal election contributed to the defeat of the Liberal Party’s Sophie Mirabella, it’s been reported.

Independent Cathy McGowan’s 439-vote winning margin in the Victorian rural seat of Indi came after a number of her younger backers allegedly engaged in electoral fraud, News Corp Australia reports.

It says they switched voter enrolments to Indi in the weeks before the September 7 election, despite living and working in other seats, including Melbourne.

More than 20 dodgy enrolments of McGowan backers are at the centre of a probe by the Australian Electoral Commission’s new integrity unit.

The Indi enrolment addresses are contradicted by home addresses in other seats, job and study locations, previous enrolment data, and profiles and output on social media platforms including Twitter, Facebook and LinkedIn, News Corp reports.

Ms McGowan won Indi with 44,741 votes to Ms Mirabella’s 44,302.

Ms McGowan told News Corp that if there was any wrongdoing, it would be on a small scale.

“Numbers of young people made their own decisions about what they would do. I would be very surprised if there were 200 who did that.”