Police say a post-mortem has revealed that Alex Fisher suffered head trauma before he died and was found Waitarere Beach.
A post-mortem carried out revealed the 10-year old had suffered head injuries, however the actual cause of death is still a matter for the Coroner to decide.
The large operation, involving staff from throughout the North Island, continues this weekend as police conduct a homicide investigation into Alex's death.
Since launching a 0800 hotline yesterday, police said they have received a reasonable response from the public and encourage anyone with further information to contact them.
"There may still be sightings of Alex and his brother Eric around Waitarere, or the forest and beach area that we're not yet aware of," Detective Senior Sergeant Neil Forlong said.
He added: "If you are not sure about what you might have seen, please contact us anyway and let the police make that judgement."
They also urge anyone who is returning home from the school holidays to check their properties for any signs of disturbance or missing items.
Meanwhile the Waitarere community are planning a candlelight memorial for Alex at Waitarere Domain tomorrow, as locals come to grips with Alex's death.
The event called "One Waitarere" will include a candle lit vigil, prayers and items from local groups. It will start at 7pm.
Police hotline: 0800 234 7437.