The Australian Federal Police has defended its prosecution of the nation's most decorated living soldier as a media leak about his arrest falls under scrutiny.

Ben Roberts-Smith was charged with murdering or ordering the murders of five unarmed detainees while deployed in Afghanistan between 2009 and 2012, after he was sensationally arrested on the tarmac of Sydney Airport in April.

Following a flight from Brisbane, the Victoria Cross recipient was filmed by Nine's media crew as AFP officers walked him off the plane.

No other media organisations were made aware of the arrest ahead of time.

The department responsible for investigating war crimes has asked the federal anti-corruption commission to probe the leak, and on Thursday, AFP Commissioner Krissy Barrett backed the decision.

'I am not just disappointed the media outlet was there, but I am determined to find out how they knew of the arrest,' she told Senate estimates.

'This could be an unauthorised disclosure and in my view anyone who disclosed that information should face consequences.

'I have no evidence to suggest the AFP provided information to the media about the date or details of the arrest.'

Other details of his arrest have been questioned by Liberal senator Michaelia Cash and One Nation senator Malcolm Roberts, who asked why he was arrested in front of his teenage daughters and why the AFP shared its official footage - which blurred Roberts-Smith's face - after the arrest.

Acknowledging the 'legitimate interest' in the issue, Ms Barrett offered a comprehensive statement.

A joint war crimes investigation into members of the Australian Defence Force deployed to Afghanistan was first launched in December 2021.

The Sensitive Investigations Oversight Board on March 31 proposed charging Roberts-Smith and on April 1 it received consent from Attorney-General Michelle Rowland, which led to the 47-year-old's arrest on April 7.

He was taken into custody at Sydney Airport due to operational reasons, the commissioner said.

The sterile environment at an airport, where people are screened and the area is contained, makes it safer for members of the public and for AFP officers to take action.

There were reports Roberts-Smith had offered to present himself to police but this was 'unviable' due in part to the seriousness of his charges, Ms Barrett said.

The AFP also makes footage available to the media to officially document an arrest and offer a source of truth in an era of misinformation.

'We take an oath that we will faithfully and diligently carry out our duties without fear or favour, without affection or ill will,' Ms Barrett said.

'The Australian public can know the AFP will determine cases on the evidence in front of us and not because of name, fame, or background of any individual, and that is the right thing to do.'

The former SAS soldier has promised to use the upcoming trial, which could take years to get to court, to clear his name.