Your fridge could be turned into a covert listening device by Queensland Police conducting surveillance.

The revelation was made during a Parliamentary committee hearing on proposed legislation to give police more powers to combat terrorism.

Authorities could turn your smart fridge into a secret listening device. Stocksy

Police Commissioner Ian Stewart said technology was rapidly changing and police and security agencies could use devices already in place, and turn them into listening devices.

"It is not outside the realm that, if you think about the connected home that we now look at quite regularly where people have their security systems, their CCTV systems and their computerised refrigerator all hooked up wirelessly, you could actually turn someone's fridge into a listening device," Mr Stewart said.

Queensland Police Commissioner Ian Stewart said the proposed new laws were necessary to keep people safe. Glenn Hunt

"This is the type of challenge that law enforcement is facing in trying to keep pace with events and premises where terrorists may be planning, they may be gathering to discuss deployment in a tactical way and they may be building devices in that place.

"All of that is taken into account by these new proposed laws."

The Counter-Terrorism and Other Legislation Amendment bill would give police more powers during and following attacks.

It would give police the power to turn existing devices into surveillance devices during a declared emergency, including by remotely installing software, when the life, health or safety of a person may be in danger.

It would also allow police the power to search a person or vehicle without a warrant during a declared terrorist emergency.

A review of emergency situation declarations for the past 2.5 years did not identify any incident which would have required the proposed extraordinary emergency powers.

But Mr Stewart said despite the rarity, the proposed legislation was still important to help police fight the terror threat.

Mr Stewart said the most likely scenario for a terrorist attack in Australia would be low-tech violence by a person or small group involving knives, vehicles, firearms or improvised explosive devices.

"The threat of a low-tech terrorist organisation inspired attack is exponentially harder to detect and disrupt," he said.

"This is further exacerbated through their use of encryption and anonymising tools to make their use of the internet and social media invisible to intelligence and law enforcement agencies."

Mr Stewart said there was an unprecedented escalation of terrorist-related activity within Australia since September 2014, with the principal threat from an extremist interpretation of Islam, while far right-wing violent extremism also posed a domestic threat.

Since 2012, about 200 Australians have travelled to Syria and Iraq to join the conflict, and there are about 40 Australians who have returned.

"And some of these returnees remain a significant security concern," Mr Stewart said.

Mr Stewart said there were about 210 Australians being investigated.

The bill is being considered by the Legal Affairs and Community Safety Committee, which is due to report by August 11.