AMCRAN

The terrorist threat to Australia has not been diminished by arrests resulting from raids in Sydney and Melbourne, and stronger anti-terrorism laws remain vital, Australia's chief spy says.

But the Senate inquiry hearing the warning was also told the new legislation to counter the terrorist threat could backfire on the federal government, by making susceptible Muslims more open to radical ideas.

Australian Security Intelligence Organisation director-general Paul O'Sullivan on Thursday defended the need for stronger legislation when he appeared before the Senate committee inquiring into proposed amendments to Australia's anti-terror laws.

He said strong powers were needed to counter the continued terrorist threat.

"A number of people in Australia are facing terrorism charges as you know," Mr O'Sullivan told the inquiry.

"I will, however, note that the threat has not abated and we need to continue the work of identifying people intent on doing harm, whether they are already in our community, or seeking to come here from overseas, or to attack Australia's interests overseas."

But the Australian Muslim Civil Rights Advocacy Network (AMCRAN) said the recent raids had shown existing legislation was strong enough to counter the threat of terrorism.

AMCRAN spokesman Dr Waleed Kadous said the new legislation could backfire by encouraging susceptible Muslims to accept radical ideas.

"Legislation is not just about law, it's about social messages," Mr Kadous said.

"It's not within my power to guarantee that the introduction of these laws will not lead to people susceptible to radical ideas falling for them as a consequence of what they see as being railroaded."

The tough sentences for advocacy crimes and the absence of a three-year sunset clause were among other concerns highlighted by the group.

ACT Chief Minister John Stanhope said Prime Minister John Howard had twice failed to assure him the legislation complied with Australia's obligations under the International Covenant on Civil and Political Rights (ICCPR).

Mr Stanhope, who has received an ASIO briefing on the terrorist threat, said he believed counter-terrorist legislation was needed in Australia.

But he said these laws could still abide by the ICCPR principals.

Australian Federal Police deputy commissioner John Lawler told the committee the legislation would "fill in many of the gaps" in the current police laws.

"Terrorism is different to other offences that the AFP investigates in that its outcomes are much more unpredictable and potentially catastrophic," Mr Lawler said.

"These powers will be used judiciously and cautiously."

NSW Council for Civil Liberties president Cameron Murphy said the clause requiring a review of the law after 10 years was too long.

He said police and other agencies would find the extra powers very difficult to give up after a decade of use.

Mr Murphy also urged the government to think of the ways in which sedition laws could be used if a different administration won office.

"It's very easy when you're in power to think these things won't be used against us," he said.

The Senate committee will resume on Friday before reporting its findings in 10 days' time.