Australia's spy and counter-terror agencies will receive a $600 million funding boost to fight the threat of home-grown terrorism, which Prime Minister Tony Abbott says "has not changed" and is still "as high as it has ever been".

Mr Abbott unveiled a suite of counter-terrorism measures on Tuesday which as Fairfax Media revealed earlier includes stronger powers for authorities to detain and question jihadists who have fought alongside terrorists overseas in countries like Syria and Iraq.

Prime Minister Tony Abbott announces the new security laws with Foreign minister Julie Bishop and Attorney-General Senator George Brandis. Credit:Andrew Meares

This includes lowering the threshold for police wanting to arrest suspected terrorists without a warrant and giving AFP greater powers to seek control orders on returning foreign fighters.

It will also be an offence to travel to designated countries where terrorists are actively operating unless there is a "legitimate purpose".