Jurors running their own criminal investigations using the internet and social media is increasingly risking Australians' right to a fair trial, two senior legal minds in Canberra have warned.

Overseas jurors have been jailed for consulting the internet during trials and while nothing that severe has happened yet in Australia, there have been close calls.

A Queensland murder trial was aborted in 2014 after a juror researched the case on Facebook and admitted it to another juror.

And last year in Western Australia, a juror was dismissed after posting on Facebook about the case.

One of the ACT's top defence barristers James Lawton said while juror misconduct was nothing new — an English jury in the 1990s consulted a Ouija board to arrive at their decision — the internet age meant jurors were finding it harder to switch off from the outside world.

"It's probably a bigger problem than we actually know about because I suspect a lot of it occurs but doesn't get discovered," Mr Lawton said.

Jurors behaving badly

Juries are supposed to only consider the details provided to them in court.

Often aspects of the crime and even the accused's criminal history are deliberately kept from the jury so as not to taint their opinions.

But Associate Professor of Law at the Australian National University, Mark Nolan, said a quick internet search could sometimes reveal all.

"There is a real risk that the deliberations of the jurors will include inadmissible evidence or evidence that's not really known to the prosecution or the defence," Associate Professor Nolan said.

"That introduces inherent injustices and illegalities."

The toss of a coin, short straws and even a Ouija board have helped juries make up their minds in the past. ( ABC News: Ewan Gilbert )

Do the crime, serve the time

Queensland, New South Wales and Victoria all have laws targeting jurors who offend.

Associate Professor Nolan said the threat of punishment worked.

"[That is a] quite good deterrent, and what's important is that the direction is given to the jury at the start of the trial, at the earliest possible opportunity," he said.

Mr Lawton also suggested ways of curbing the desire to check information online.

"I think we need to give juries a way of investigating, but put limits on it," he said.

"Perhaps give them a data base in terms of questions they might want to ask ... so they aren't tempted to go to Google or to go to their smartphone during the trial."

'Hard for juries to put emotions to the side'

Mr Lawton said the internet age should also prompt a rethink for jurisdictions like the ACT, where juries are required for all sex offence and murder trials.

"They are the sort of trials where it's very hard to put emotions to one side and very hard to put initial prejudice against the type of offence to one side," Mr Lawton said.

Mandatory jury trials are thought to better meet community standards and save time by avoiding the need for judges to produce lengthy written reasons justifying their decision.

But Mr Lawton said sometimes it was important to see how a decision was reached, particularly in difficult cases.

He suggested the ACT might be better served by a model similar to that of NSW where offenders could elect to have a judge alone trial, under particular conditions.