Pauline Hanson's chief-of-staff investigated over flights

A Pauline Hanson staffer says an investigation into him flying a light aircraft without the right licence is a 'political witch-hunt'.

One Nation leader, Senator Pauline Hanson (left) and her political advisor, James Ashby, pose for a photograph in Birdsville. Source: AAP

Pauline Hanson's chief-of-staff James Ashby is being investigated for allegedly flying a light aircraft without the correct licence.

The Civil Aviation Safety Authority inquiry reportedly centres on whether he was acting as a commercial pilot when he used a Jabiru J230 to fly his boss around Queensland during the 2016 federal election campaign.

If it is found Mr Ashby holds a recreational certificate or licence, but was operating as a commercial pilot, he could lose his registration.

Mr Ashby says the investigation is a "political witch-hunt".

"This matter has already been investigated by Recreational Aviation Australia where they found no case to answer," Mr Ashby said in a statement on Thursday.

"I will comply with CASA's request for documents, however, this is just a further waste of taxpayers' money where their findings will result in the same outcome as previous investigations."

A recreational certificate only allows pilots to fly a two-seat recreational registered aircraft in uncontrolled airspace during daylight hours within 25 nautical miles of the departed aerodrome.

A recreational pilot licence allows flights of larger aircraft in controlled airspace, and a private pilot licence is another step above that.