No promise Indi issue can be avoided: AEC

The Australian Electoral Commission cannot guarantee there won't be a repeat of the Indi experience at the next federal election, where 28 people are being investigated for possible voter fraud.

But electoral commissioner Tom Rogers is confident that systems are place to protect the integrity of the electoral system as far as possible.

Mr Rogers told a Senate estimates hearing on Tuesday that when dealing with 14.7 million voters, guarantee is not a word the commission likes to use.

"I'm confident of the systems we have in place," he told the hearing.

"Does that mean that we can always prevent something that is alleged to have occurred in Indi ... I can't give you that guarantee."

Independent Cathy McGowan defeated sitting Liberal frontbencher Sophie Mirabella by a slim margin of 439 votes in the Victorian regional seat of Indi in the 2013 election.