Asked about the alleged involvement of a former British soldier, a Fiji police spokesman told an ABC News reporter: "Those are the allegations that were made. The investigations are continuing."
The veteran has not been identified - and authorities have not confirmed his role - but large numbers of people from the Commonwealth nation serve with the British army. The archipelago was a British colony until 1970.
Fiji's director of public prosecutions released a list of the latest 16 people to be arrested and asked that the court keep the group in jail "due to the seriousness of the charges and the ongoing police investigations".
They will appear in court again on August 26. Several others have been arrested on charges of sedition in the past week.
Fiji's police said authorities had begun making arrests recently after receiving reports of "training of a seditious nature being conducted in the interior of Ra by certain groups".
Police commissioner Ben Groenewald said officers had not confiscated weapons and had been unable to confirm that guns were involved.
Authorities have reportedly been dispatched to Ra to persuade villagers not to support the separatists.
Fiji has had a series of coups since 1987 which have been largely linked to tensions between the indigenous population and the Indian community, who are descended from labourers brought to the islands by Britain in the 19th century.
The last coup was led in 2006 by Frank Bainimarama, a military commander who won a long-delayed election last year.
He claims he staged his coup to soothe tensions between the nation's rival communities, but his efforts to assuage the Indian community have angered some members of the indigenous population.