The head of the Australian Border Force, Roman Quaedvlieg, has gone on leave following an external investigation, the Turnbull Government has confirmed.

It understood that the cause of his leave was related to personal behaviour and not the fact that two Australian citizens were mistakenly detained and sent to the Christmas Island detention centre several months ago.

The former Queensland and Federal Policeman became Commissioner of the ABF in 2015.

Australian Border Force commissioner Roman Quaedvlieg. Alex Ellinghausen

Immigration Minster Peter Dutton is currently taking annual leave. A spokesman for acting Minister Michael Keenan said Mr Quaedvlieg "is on leave".

"A matter is under consideration by appropriate authorities. There will be no further comment until that process is complete," the spokesman said.