Police in the Papua New Guinea province of West New Britain are working on a possible breakthrough in the investigation into the disappearance of five scientists nearly two months ago.
The five staffers from the Institute of Medical Research, along with the three crew of their banana boat, disappeared at sea at the beginning of August.
A search was called off two weeks ago but police believe the group may be victims of piracy and has been kidnapped.
The West New Britain police commander, Senior Inspector Thomas Reu, says they are continuing to investigate this possibility.
He says on Thursday a relative of one of the missing researchers received a demand for money from an unknown source.
"The unidentified caller is asking for phone credits worth 1000 kina to be given to them and also he's asking for ten thousand kina to be given too. So I am now in the process of running a request letter to both [telecoms] companies, Digicell company and B-Mobile company to see if they could assist."