A toddler has died of head injuries from a suspected assault in Adelaide earlier this month, with police launching a murder investigation.
No one has been charged over the death of the 17-month-old boy identified as Ronan.
Detectives are focusing on a two-day period when the boy was being cared for by family friends at a home in suburban Glenelg North.
The child was returned home on June 7 and soon after taken to the Women's and Children's Hospital by ambulance when his father could not rouse him.
He died on June 9.
Detective Inspector Mark McEachern says the boy's injuries would not have been obvious.
"Ronan's been returned home, apparently asleep. We suspect he sustained injuries prior to that," Insp McEachern said on Tuesday.
"We have been provided with an explanation of how Ronan's injuries occurred.
"We're not satisfied with the explanation that's been given to us."
Detectives want to hear from anyone who may have seen the boy in the lead-up to his death.
They are particularly interested in talking to anyone who heard or saw anything involving a young child in Ferguson Street at Glenelg North on the afternoon of June 7, including anyone with dashcam footage from that afternoon.
