Police in Christchurch say a toddler who died was the victim of an extremely violent assault.
Detective Inspector Greg Murton said police had launched a homicide investigation into the death of 15-month-old Ihaka Paora Braxton Stokes, who died last week after being found unconscious at a Bryndwr property.
The boy was taken to Christchurch Hospital's emergency department but died soon after arriving.
Mr Murton said the child suffered multiple blunt force injuries and broken bones.
"The scene examination and post-mortem results have confirmed that Ihaka was the victim of an extremely violent assault, or assaults, and has subsequently died [of] his injuries."
Mr Murton said they had spoken to Ihaka's mother and stepfather, who live at the Truman Road house, as well as a large number of others.
A team of 12 investigators is working on the case but no charges have yet been laid.