Defence official stumbles when asked what minister Steve Ciobo's job entails

Steve Ciobo is the Defence Industry Minister but it appears officials at the Department of Defence don't seem to know exactly what his job entails.

During Senate estimates hearings today, Labor Senator Penny Wong asked John Geering, the First Assistant Secretary Ministerial Executive Coordination and Communication Division, what Mr Ciobo had responsibility for.

Mr Geering's response was to stutter, pause, then say he'd take the question on notice.

That means he will research the answer and provide it in writing at a later date.

During the stumbling, Foreign Minister Senator Marise Payne appeared to whisper to Angus Campbell, the Chief of the Defence Force: "Fair to say I'm enjoying this."

Senator Payne's office says she was discussing an unrelated matter with General Campbell.

A man who should know is Barnaby Joyce; he was on the National Security Council with a former Defence Industry Minister.

"Defence Industry Minister has the, ah, role to assist with the huge appropriation which is the defence budget," Mr Joyce said this afternoon.