The Fiji Sun reports the group of Fiji men was sent to Bouganiville by a Nausori-based security company called Tri Unity which has a contract to protect a gold mine on the island.
The newspaper says Tri Unity is a subcontractor to Ronin High Risk Security, which is headed by the former British SAS soldier and leader of the gunmen in the May 2000 Fiji coup, Ilisoni Ligairi.
Founding members of Mr Ligairi's now disbanded Counter Revolutionary Warfare Unit, the CRW, are also part of his company.
The report says both Mr Ligairi and his CRW instructor Maloni Namoli have been involved in the training of Tri Unity recruits.
A Suva lawyer and Tri Unity director Apaitia Seru, who was forced to resign as attorney general in the Rabuka government in the mid 1990s, is quoted as saying he was not aware of the Bougainville contract since he had not attended any board meetings.