Former cabinet minister Nigel Scullion charged taxpayers for $80,000 in charter flights for "official duties" during the election campaign even though he was retiring from politics.

Mr Scullion led a team of National Party politicians who incurred huge bills during the election campaign which they said related to official duties or parliamentary business.

Former cabinet minister Nigel Scullion incurred large charter flight costs during the campaign despite retiring. Credit:Alex Ellinghausen

However, electoral law experts have said the line is too easily blurred when ministers can arrange "sham" meetings and functions to coincide with pre-planned campaign events.

Mr Scullion was a Northern Territory senator based in Darwin and necessarily incurred large expenses as indigenous affairs minister travelling around the region.