A 22-year-old man has been charged with the murder of 15-month-old Ihaka Paora Braxton Stokes in Christchurch.
"The homicide investigation has led to a man known to the victim being arrested today," Detective Senior Sergeant Michael Ford said.
"For legal reasons we cannot confirm the identity of this man."
The man will appear in the Christchurch District Court tomorrow.
Ihaka suffered multiple blunt force injuries including broken bones, a post-mortem examination found.
Police and St John were called to the house at Truman Rd, Bryndwr about 10.30pm on July 3.
Ihaka was found unconscious with unexplained injuries.
He was transported to the accident and emergency department at Christchurch Hospital and died shortly afterwards.
More than 42 people have been interviewed by officers working on the homicide investigation codenamed Operation Truman.
Detective Senior Sergeant Michael Ford said the investigation into Ihaka's death was ongoing.
"We have seven detectives working full time on Operation Truman and they will continue to work tirelessly to ascertain why a 'typical' day ended so tragically for Ihaka" he said.
On Saturday Ihaka's aunty Marrisa Hunton -- sister of Ihaka's heavily pregnant mother Mikala Stokes -- said his death was not a result of foul play.
"This little boy was not murdered he died in a terrible tragic accident," she wrote on Facebook.
Ms Hunton blasted media outlets "out for a story" and said the family had been sent "horrible comments" on social media by "trolls and people who have no idea".
Police could not comment further on the murder charge or the accused as the matter was now before the courts.