A phone-tracking system used to better understand where two people infected with coronavirus roamed in Adelaide is the same system harnessed by SAPOL for criminal investigations, the state's Police Commissioner has said.

Key points: Phone metadata is being used to track an infected couple's movements around Adelaide

Phone metadata is being used to track an infected couple's movements around Adelaide SA Health is following the lead of South Korea in using phone tracking to contain coronavirus

SA Health is following the lead of South Korea in using phone tracking to contain coronavirus SAPOL says it's the same phone metadata used regularly for criminal investigations

Commissioner Grant Stevens said police used a program that only required a phone number to give operators "a download of where the phone had been used".

"We're doing that to assist SA Health in tracking down the movements of the two people concerned so we can do our best to identify any people who might have been exposed [to coronavirus]," he told ABC Radio Adelaide.

"It's used quite frequently for criminal investigations."

Commissioner Stevens said a legislative "threshold" had to be met "in terms of suspicion of a serious offence" before the software could be used.

This real estate office in Adelaide closed as a precaution after dealing with the couple from Wuhan. ( ABC News: Richard Davies )

"Or we need to be able to demonstrate there are life-threatening circumstances that warrant the use of the technology.

"In this case, we think there's a genuine risk to public safety, and certainly there's community concern about this, so it's one of the occasions we elected to use it."

The couple, both aged 60, travelled from Wuhan in China to visit relatives and attended a house auction at Firle last month, prompting the associated real estate business to temporarily close its Dulwich office as a precaution when it became clear the couple was carrying the coronavirus.

The Chinese couple remain isolated in hospital in a stable condition and have been cooperating with authorities to map out their movements while in Adelaide.

SA Health inspired by South Korea

SA Health chief public health officer Nicola Spurrier said if there was any suggestion that affected people "haven't been isolated when they are symptomatic, then it was very important to try and get as much information as we can".

"Particularly as they have come from a foreign country into Australia and, obviously, as tourists they are not expected to be so familiar with the names and places where they may have been," Professor Spurrier said.

She said the department used phone tracking after becoming aware that South Korea was using a similar system in response to the outbreak of the coronavirus.

"I'm not sure at this stage whether it will make a difference but it seemed to me, in this situation where we are trying to contain the virus, and we have these two cases where we are unsure of their level of isolation, it would be a very useful thing to look into," Professor Spurrier said.

Metadata collection a Commonwealth law

Phone metadata has been a contentious issue for privacy advocates worldwide, particularly in Australia where data retention laws mean phone and internet companies have to save the information for two years.

This included location data that was collected every time a person used their phone for texting or calling — recording where the interaction took place and for how long.

Location data was also collected every time a device connected to or pinged off a phone tower as part of its regular functionality.

The data combined to create a veritable tracking device out of smartphones, roughly logging a carrier's location every 20 minutes or so.

That information can be made available to government departments, police, and security agencies.

SAPOL would not comment further on the methodology of its own system but said it was used under the framework of the Telecommunications (Interception and Access) Act of 1979 and gave a general indication of where the phone had been used.

Commissioner Stevens said they used data that came "from the use of the phone, not the physical device" and it was not affected by whether that device had its location services switched on or off.