The Papua New Guinea High Commissioner to Australia, Charles Lepani, says his government had to declare a state of emergency in the Southern Highlands to protect its petroleum and gas resources and restore order.
Soldiers and extra police are expected to be sent to the province within two weeks.
Mr Lepani says the oil and gas resources are threatened by a deteriorating law-and-order situation while the provincial government has been accused of maladministration.
The Southern Highlands governor, Hami Yawari, who has been suspended along with his government, rejects the accusations.
"There is no maladministration. All our books everything is very clear. We have had the auditor general checking the books, the administration is functioning. This is pure politics. This is pure politics by the national government. I don't why this is happening."