Madang Provincial Police Commander, Chief Inspector Ben Neneo, confirmed the killing is yet to get a full report on the incident.
PPC Neneo further said police are yet to establish the motive behind the incident.
Meantime, the father of the deceased, Governor Peter Yama, has condemned the killing of his son.
He said the manner in which his son was killed was gruesome and he believed it was meant for him.
He added that his son, who was mentally unstable, did not deserve to be killed in such a manner.