Police have launched an investigation into a Masterton assault that has left a three-month old baby with critical injuries.
In a statement, officer in charge of the investigation Detective Senior Sergeant Barry Bysouth said police were called to an incident at a residential Masterton address shortlyafter 8.30pm on Thursday.
A three-month-old baby was found at the address with critical, non-accidental injuries.
Ambulance staff immediately transported the child to Masterton Hospital and then on to Starship Children's Hospital in Auckland.
Bysouth said police were investigating the assault while also focusing on supporting the baby's family.
"This incident is traumatic for all involved. An investigation is under way and police are working hard to determine the circumstances of the assault.
"An equally important focus for the investigation team is the support of the whānau and baby."
He said co-operation of the whānau, friends and the wider community was vital to the investigation.
Police expected to finish the scene examinations of two Masterton properties and one vehicle yesterday.
Anyone with information relating to the assault is urged to contact Masterton Police directly or via the 105 number, referencing file number 220617/7497.