There are claims in Papua New Guinea that a group of Fijian soldiers giving military training to rebels in Bougainville island have been in the country for five months.
The Bougainville Affairs official, Dr Ted Wolfers, says they've been coming and going freely and evading immigration checks.
Dr Wolfers attributes this to the mutual immigration agreements in member states of the Melanesian Spearhead Group.
"At least a couple of them have been in and out three times this year, since the middle of the year, and of course given the relative freedom of movement amongst the Melanesian states, it's not particularly easy to pick people up."
A Fiji diplomat is in the rebel-held area of the Papua New Guinea island of Bougainville to negotiate the transfer of six former Fiji soldiers who've been giving military training to locals.