The findings, which are currently out for peer review, come as attention turns to the next two appointments to the court, with Geoffrey Nettle set to retire in December and Virginia Bell to leave in March next year. Four justices will retire in as many years.

The federal government has the power to appoint judges with no oversight, unlike the US where Supreme Court nominees must be confirmed by the country's Senate.

Professor Zoë Robinson, who works at the Australian National University's school of politics and international relations and is the lead author on the research, said it was not surprising the ideological leanings of High Court justices made it more like the US Supreme Court.

"The government just has discretionary authority to appoint whoever they want with no oversight. Why would we think that the government's not going to utilise this one really strong lever to put somebody in power who can implement or at least can be of the same mindset to their policy profile," Professor Robinson said.

Professor Robinson's team analysed newspaper reports in the six months leading up to a judge's appointment to the High Court and then their voting record to assess ideological impact on decision making. The study scored the ideological position of each justice since the appointment of Michael Kirby in 1996.

The paper, which Professor Robinson co-authored with Patrick Leslie and Dr Jill Sheppard, concludes a judge's ideological position before their appointment to the court is a reliable predictor of their voting pattern in both rights and non-rights based High Court cases.

"To be really clear, we're not saying the justices are conscious policy seekers who are seeking to implement the policy of the government that appointed them. That's absolutely not what we're saying," Professor Robinson said.

"But we're saying that it's rational to think there's a connection between who the justice is and who appointed them and the outcomes that will eventually come from it. Otherwise, why would we care so much about who's appointed to the court?"

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As Australia did not have a bill of rights, there was perhaps less attention focused on the make-up of the High Court, Professor Robinson said.

"I think there's a really strong sense that without a bill of rights - without the apex court deciding on a bill of rights, it's relaxed that kind of social context that would really put the court in the thick of really important social questions. So the court hasn't been seen to be an important player," she said.

Professor Robinson said a bill of rights could change the way the High Court was seen in a political context.

"If Australia does go down that path and eventually adopt some form of bill of rights, when ... there's a correlation between a justice's ideology ... and their voting behaviours, does that suggest that when we have a bill of rights the judges will become more and more important in the Australian system of government? Possibly," she said.

Professor Robinson said the High Court appointment process, which had no constitutionally binding requirement for consultation, meant less attention was given to the make-up of the High Court.

"We probably should pay more attention. The High Court makes decisions on really important issues that touch the lives of everyday Australians. I just think there's this veneer of legalism that hangs over the top and it seems to put it out of touch, out of reach of ordinary Australians in terms of comprehension of the issues before the court," she said.

Court watchers expect the federal government to announce the next two keenly awaited appointments to the High Court as early as next week.