Resurrected federal government minister Mal Brough says he has not been interviewed by Australian Federal Police one year after admitting he encouraged a staffer to procure copies of the diary of his political rival, the former speaker Peter Slipper.

Labor has written to the AFP following the revelation, demanding police urgently resolve the investigation.

Mr Brough is under renewed scrutiny after Prime Minister Malcolm Turnbull appointed him Special Minister of State – a job that oversees parliamentary standards and entitlements.

Mr Brough was one of Mr Turnbull's key backers in the leadership spill that ousted Tony Abbott two weeks ago. He was a former minister in the Howard government but Labor says his elevation into the ministry was a reward for helping Mr Turnbull seize the top job.