Help from the Kolombangara Island community in Solomon Islands was instrumental in the rescue of 20 dolphins being held in captivity.
Western Province police commander Mathias Lenialu said dolphin trapping was common in the area, but it is illegal and people catch the mammals secretly.
Mr Lenialu said the Ministry of Fisheries and Marine Resources had raised concerns with the community on Kolombangara.
"With the crime prevention strategy recently implemented by the Royal Solomon Islands Police Force, now we have created all the crime prevention committees out in the communities, so people now usually come forward to assist police with information."