Australia's top-secret air marshals are under a cloud after Virgin Blue cast doubt on the need for the expensive anti-terrorist program.

The cut-price airline wants the $26 million-a-year program reviewed, but the Federal Government said yesterday the anti-hijack measure had been very successful.

In a submission to a parliamentary aviation inquiry, Virgin Blue security manager Phil Scanlon said air marshals were introduced without proper consultation.

"By contrast, the UK Government, whose aviation sector operates in a more threatening environment, saw no requirement to introduce (air marshals)," he said. "Whilst Virgin Blue has fully participated in the program, we are yet to be fully convinced of its true value."

Virgin's concerns are a blow for the air marshal program when high-level talks are under way to expand the initiative to more international destinations.

The anti-hijack measure started on domestic routes in December 2001 in response to the September 11 terrorist attacks in the US.

It was later extended to Qantas flights between Australia and the US and Singapore.

About 130 armed marshals patrol the skies. They work under federal police direction and earn about $70,000 a year.

The officers are paid by the Federal Government, but there is a cost to airlines in forgone revenue from seats taken by marshals. Mr Scanlon said the cost to Virgin Blue had been substantial.

"We believe there is a case for reviewing the program to determine whether it is beneficial," he told Federal Parliament's joint committee of public accounts and audit.

Australian Federal Police Association CEO Jim Torr, whose union represents air marshals, said they played a key role.

Justice Minister Chris Ellison said he was disappointed and surprised by Virgin Blue's stance. "I totally reject that we brought in the program without any consultation," he said.

He said the program deterred terrorist attacks and was now being considered by countries including Britain. An international air marshals" conference will be held in Australia in November.

Virgin Blue says it won't be introducing an additional fuel surcharge at this stage, but will look at its fare structure.