Four men have been arrested in relation to unrelated assaults that took place on the Kapiti coast the same night 17-year-old Izak Millanta died.
The men, aged between 19 and 26, have been arrested on charges of assault, fighting in a public place and injuring with intent to injure.
One of the men is due to appear in Porirua District Court next Tuesday and the remaining three have been given warnings.
Detective Inspector Mike Johnson said that while investigating Izak's death, police became aware of further alleged fights that took place in the carpark area of the Kapiti Lights complex and surrounding area on the same night and following morning.
It appeared some people who witnessed or knew about the incidents did not alert police, said Senior Sergeant Alasdair Macmillan.
Izak was found by police unconscious in a carpark at the back of the Coastlands shopping area carpark at Paraparaumu about 3am on Saturday 11 August.
He died in Wellington Hospital the following day.
A 25-year-old man has been charged with assaulting him and was remanded in custody after a court appearance this week.