Police have formally named the boy whose body was found on Thursday afternoon at Waitarere Beach.

He was 10-year-old Alex Fisher, who was a student at Ohau School near Levin.

Police said yesterday's post mortem examination has revealed he suffered head injuries.

A big police homicide team is working on the investigation into the boy's death through the weekend.

Police said they've received a reasonable response to their request for information from the public but still want to hear from anyone who hasn't come forward and who may have seen Alex or his older brother Eric around Waitarere township or the forest or beach areas.

Police want people who may be returning home to Waitarere this weekend to check for anything unusual or signs of disturbance or anything missing.

The number to call is 0800 234 7437.

Police said the cause of death is a matter for a coroner.