
Photo: RNZ/Reece Baker
Police earlier said an investigation was under way, after the baby was found with critical injuries at a property on Seabury Avenue about 5.30am Sunday.
The baby was initially transported to Palmerston North Hospital, before being airlifted to Starship Hospital in Auckland.
A scene examination of the Foxton Beach home was completed earlier in the week and a homicide investigation has now commenced.
Deegan said several people had already been spoken with and the police continued to liaise with medical experts to establish how the baby boy came to be injured.