A senior official in the Papua New Guinea's government says landowners in Hela Province have wasted all the money they've made from oil and left their families struggling to get by.
Rose Kualke Singadan of the Department of Environment and Conservation says during a recent visit to the province she saw widespread poverty and suffering as a result of the men taking their earnings to the capital, leaving their women and children alone in remote villages for up to years at a time.
She says there's been no investment in medical facilities, education services or roads, which have all become very run down.
Ms Singadan says the men, whom she calls oil sheiks, should take stock of their spending.
"Just wasting it on alcohol, nightclubs and in hotels and other activities that are not beneficial. I believe there's a lot of other inexplicable activities such as prostitution and mixed marriages and promiscuous behaviour in the cities that leads to polygamous marriages away from their way of life."
Rose Kualke Singadan says landowners must be educated to spend oil and gas earnings sensibly in the lead-up to ExxonMobil's multi-billion dollar gas project.