Papua New Guinea is battling what it says is a plot by the self-proclaimed king of a separatist region to use mercenaries to train a militia deep in the jungles of an island rich in gold and copper.
The government is calling for the expulsion of the eight alleged mercenaries, former Fijian soldiers who claimed to be missionaries when they flew into the autonomous island of Bougainville three weeks ago.
The men, two of whom are believed to be British-trained and to have served in Iraq and Afghanistan, were reported to be the advance guard of a much bigger force.
Papua New Guinea's high commissioner to Fiji, Peter Eafeare, told the Australian Broadcasting Corporation that he received information in May that 300 former Fijian soldiers were planning to travel to Bougainville. The men were allegedly led by Ilisoni Ligiari, a former member of the British SAS, who took part in Fiji's 2000 coup in which the country's ethnic Indian prime minister was held hostage with his cabinet for 56 days.
The affair has caused uproar in Papua New Guinea, where eight years ago the government employed a British security company in a failed bid to quash Bougainville's secessionist movement.
More than 10,000 people have been killed since Bougainville descended into civil war in the early 1990s. The conflict was sparked by islanders' anger that they were not benefiting from the hugely profitable Panguna gold and copper mine.
The granting of autonomy in June brought hopes of peace and stability, but some fighters still hold out in remote areas.