Australian Border Force chief Roman Quaedvlieg has been sacked after nearly 10 months on paid leave for "misbehaviour" and failing to uphold his oaths by helping get his girlfriend a job on the force.

Mr Quaedvlieg swiftly hit back, saying he would consider his options and hinting he might take legal action.

Home Affairs Minister Peter Dutton announced on Thursday that Mr Quaedvlieg had changed recruitment processes and carried out other activities to help his partner get a job at Sydney Airport. He had also failed to disclose his relationship with the woman.

Roman Quaedvlieg Credit:Alex Ellinghasuen

"Needless to say, it is extremely unfortunate that it was necessary to terminate Mr Quaedvlieg's appointment," Mr Dutton said. "He has provided long and conspicuous public service in the critically important areas of law enforcement and national security.