The immigration department is working with police to investigate allegations border officials are involved in serious criminal activity.

Staff from Australian Border Force and the agriculture department have allegedly been working with crime gangs and drug and tobacco smugglers, Fairfax reports.

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The department said the matters raised were not new and remain under active investigation by the Australian Commission for Law Enforcement Integrity.

Liberal frontbencher Josh Frydenberg says the allegations are being dealt with appropriately.

“Such behaviour will not be tolerated and we’ll take every possible measure to ensure that those people, if they have behaved in a way that is criminal, face the appropriate justice system,” he told ABC TV on Thursday.