Papua New Guinea police have arrested four bank staff and a villager over a sophisticated 400,000 US dollar bank heist.
The Bank South Pacific branch at Kerema in PNG's Gulf Province was hit last weekend in a highly organised raid spanning two cities.
Police believe bank workers provided vital information to two criminal gangs in Port Moresby and Kerema.
Separate armed gangs took members of the BSP Kerema branch manager's family hostage in both cities before making the robbery the following day.
They forced the manager to open the Kerema bank, empty the safe and an ATM.
The robbers then drove off before fleeing Kerema in a dinghy believed to belong to the arrested villager.
Police have told PNG's Post Courier newspaper they believe bank staff assisted with information and investigation teams are working in Kerema and Port Moresby.
Gulf police commander Heni Vagi says 20,000 dollars has already been recovered.