An Australian who heads a trade union in Fiji is in prison there.
Unions there say Air Pacific pilot Shalend Scott, 37, was arrested as part of an anti-union crackdown.
He has been in prison for a week, but news of his arrest has only just emerged, the ABC reported on Monday.
Mr Scott is the secretary of the Fijian Pilots' Association.
The Australian and International Pilots' Association has written to Qantas management asking them what is being done to help Mr Scott.
Qantas owns 46% of Air Pacific and has two directors on that company's board.
A spokesperson for the Australia's Department of Foreign Affairs says Mr Scott was charged with having unlawful access to documents and that consular officials were making representations to senior members of the Fijian government.