Mayo by-election candidate Rebekha Sharkie has called for a parliamentary inquiry over the use of sophisticated data mining software to target voters.

Key points: Rebekha Sharkie has called for an inquiry into data mining software used to target voters

Rebekha Sharkie has called for an inquiry into data mining software used to target voters The Liberal Party is using i360 software in the Mayo by-election

The Liberal Party is using i360 software in the Mayo by-election The program was used by Donald Trump and for Brexit

Ms Sharkie's call for an investigation into the use of the software was prompted by the reinvigoration of debate over border protection by her opponent, Liberal candidate Georgina Downer, in the lead-up to the July 28 by-election.

Ms Downer criticised Ms Sharkie's calls to resettle asylum seekers living on Manus Island in New Zealand, warning that a "softening" of policy would see a resurgence of people attempting to make the journey by boat.

But Ms Sharkie questioned the timing and motivation behind Ms Downer's comments, with less than two weeks to go until polling day in the South Australian electorate.

"I think that more than likely this is part of the i360 information sourcing program that the Liberal Party pay $25,000 a month for subscription," she said.

"I think the public should be quite concerned when unwittingly information is sourced about them from a multitude of data bases — social media and other data bases — in order to try and then pinpoint voters that they see as marginal voters and issues that they want to press them on."

The South Australian Liberal Party used the i360 program for the March state election campaign to target messaging at certain voters in key marginal seats, in an election which ended 16 years of Labor government in SA.

It was the first time the program had been used for an election outside of the United States.

It is understood the software is being used again by the Liberals in their Mayo campaign.

Ms Sharkie said she would move to establish a parliamentary inquiry into the use of data mining software if her bid for re-election succeeded.

"Ultimately I think people should have far more knowledge of the information that is being sourced about them without their knowledge and most likely without their consent," Ms Sharkie said.

"I actually think this is an issue that needs to be taken into the Parliament along with truth in political advertising — and if I'm re-elected I most certainly will do that."

Downer declines to comment on i360

Ms Downer said her warnings about changes to border protection policies were not motivated by geotargeting to win votes, and it was a current issue because of the interception of a boat off northern Australia last month.

"These comments I made are in relation to reporting over the weekend that people smugglers are still looking towards Australia as a destination and we have reports that a boat was turned back and returned to Indonesian waters in the last few weeks," she said.

"I've made those comments in the context of that article and that reporting and I've also made those comments because ultimately I don't want to see us ever give an inch to the people smugglers through softening of our strong border protection policies."

She declined to comment on the use of i360 in her campaign.

"My campaign has been focused on grassroots campaigning — I've been door-knocking, I've been attending community events, I've been meeting with members of the community, talking to them about the issues that are most important," she said.

Inverbrackie Detention Centre spawned heated debate among the community after plans were announced in 2010. ( Chris McLoughlin: ABC News )

Asylum a hot topic in Mayo

Ms Downer said border protection was one of the issues regularly raised with her by voters while on the hustings in the Mayo electorate.

"They're very concerned about prospects of softening of border protection policies," she said.

Once the home of now-closed Inverbrackie detention centre, the Federal Government's border protection policies have long been a hot topic in Mayo, a seat which takes in the Adelaide Hills.

The detention centre attracted vehement opposition from some of the community when first announced, amid concerns about the impact new arrivals could have on nearby Hills communities.

In its years of operation between 2011 to 2014, Inverbrackie remained a controversial subject for Adelaide Hills residents, with some opposed to the policy of mainland detention, while others welcomed the economic benefits of having the centre nearby.

i360 profiles voters and issues

The i360 program was developed for the Republican Party in the US, with the backing of billionaire moguls Charles and David Koch, to integrate publicly available data to build voter profiles.

It works on a cloud platform, providing information on voters and messaging to users on an app on their mobile phone.

The software has also been adopted by the Victorian branch of the Liberal Party.

The system integrates information drawn from grassroots campaigning — doorknocking and voter canvassing — to allow parties to work out messaging and target audiences in key marginals.

It also works with NationBuilder, an electoral database used by Donald Trump and for Brexit, which is also used in Australia by both major parties.

Cambridge Analytica's data plunder of Facebook users has raised global concerns about how information is securely stored and used. ( Getty Images: Chris J Ratcliffe )

How secure is the information?

Earlier this year, members of the Victorian Liberal Party complained to the state director after their information was used as part of a battle for power ahead of the state council, raising concerns about how many people have access to sensitive voter data held by political parties.

Russia's alleged cyber interference in the 2016 US election also raised red flags about the protection of voter information used by political parties, while Facebook's massive data leak to Cambridge Analytica has raised further concerns about how user information garnered from social media platforms are being used.

In light of ongoing concerns about the protection of sensitive information, the Federal Department of Finance has now granted $300,000 to four big Australian political parties to bolster the security of their constituent management systems.