The Papua New Guinea police say the clan of a man who was beaten while being taken into custody for spitting betelnut had a right to protest at his death.
Two police officers have been charged with the murder of the man who was in his 40s and from the Talasea district in West New Britain.
The acting police commissioner Tony Wagambie says stores were looted and police cars damaged after the man's clan came down to the provincial capital, Kimbe, following his death.
But he says police suspect opportunists from the settlements may have taken advantage of the relatives' legitimate protest.
"Most of them they were genuine, they come to see the Police Authority in Kimbe because they rightfully said the spittle of red betelnut doesn't warrant the killing of a man, which is very true. So I think the opportunists, other people joined in, must have come and went overboard."
Tony Wagambie says he is waiting for a report on the extent of the damage in Kimbe.