The Fiji-based Pacific Centre for Public Integrity has called on Air Pacific to explain why its Executive Director was bumped off the flight from Suva to Tonga on Wednesday.
Angie Heffernan says she arrived at the airport almost two hours before the flight with a confirmed ticket.
Ms Heffernan was on her way to Tonga to provide training at two separate NGO and media workshops as pat of the PCPI's regional Rights to Information campaign.
While in Tonga, Ms Heffernan had planned to meet with Pacific Islands Forum officials to lobby on the lack of action taken by the Fiji military regime to restore parliamentary democracy in the country.
She says that when she checked in for her flight she was told that she was on standby and did not have a confirmed booking.
Air Pacific staff later told Ms Heffernan that she was unable to take the flight because of a storm in Tonga.
She says she is now waiting for the airline to confirm her flight arrangements for Friday.