Time to review terrorism threat level: Lay

Victoria Police Chief Commissioner Ken Lay agrees it is time to review, and likely increase, Australia's terrorism threat level.

Mr Lay said the risk of a terrorist attack on home soil, linked to unrest in the Middle East, had reached a new high in the 13 years since the September 11 terror attacks in the US.

"There is no doubt that there are some concerns about what it happening in the Middle East, and some Australians who have been there and are coming back," Mr Lay told Fairfax Radio on Wednesday.

"I think it is probably an appropriate time to have a think about the (threat) level at the moment.

"The risks are probably as high as they have been since September 11."

Mr Lay said Victoria Police was preparing internally to address the increased terrorism risk and, should Australia's official terrorism alert level increase, then security at major events would be further reviewed.

"We've got no indication at all of a threat to any specific event in Melbourne," Mr Lay said when asked about the AFL grand final and Melbourne Cup.

"We've very confident that current processes are in place to mitigate any threat, but then again we're in a very dynamic environment."

He said the public needed to be aware and alert to the threat, and the most visible change should the threat level increase would be an increase in public information.

Mr Lay also said Victoria Police had excellent relationships with the state's Muslim community.

His comments came after outgoing ASIO chief David Irvine told ABC television the spy organisation was actively considered raising Australia's terror threat level, from medium to high.

Opposition Leader Bill Shorten said Labor had not been briefed on any changes to the terrorism threat level but had confidence in the national security agencies.

"It's important on one hand not to be complacent, but on the other hand not to scare people unnecessarily," Mr Shorten told reporters in Melbourne on Wednesday.

"I will wait until our security agencies form a view about changing our threat levels before commenting."