Use fake guns to test security, govt told

Airports should resume the practice of using fake guns to test their security regimes, a damning report on passenger screening suggests.

And the government must make sure all X-ray machines and metal and explosive trace detectors are up to date.

An audit of passenger security screening at domestic airports has found that minimum standards have been established, but the government had no way to make sure screening was effective or whether airports were sticking to the rules.

It doesn't have meaningful performance targets or enforcement strategies for passenger screening and doesn't direct resources to areas with a higher risk or non-compliance, the Australian National Audit Office says.

The use of replica guns in carry-on luggage to test security systems stopped in March 2014 amid problems with firearms licensing and work health and safety concerns.

More than two years on, the program is still suspended, although the infrastructure department told auditors other "test pieces" with the same amount of metal as a handgun are put in carry-on luggage instead.

The audit report says if tests of the system are to simulate realistic threat scenarios, the department needs to address the issues and start using fake guns again soon.

Outdated security equipment was supposed to have been replaced by the end of 2015 but almost a year before then the department decided not to go ahead with this, the report says.

But after it got the draft audit report in June, the department told airports they would have to replace old metal detectors and explosive trace detectors by July 2017 and X-ray machines by July 2018.