'This little girl deserved better': Baby's death declared a major crime

A baby girl has died more than a year after critical head injuries were inflicted upon her when she was just six weeks old, South Australian police say.

Inspector Greg Hutchins, from the Major Crime Investigation Branch appeals for more information surrounding the death of a baby in South Australia. Source: AAP

The death of a baby girl who suffered a severe brain injury has been declared a major crime by South Australia police.

The girl, who was born on April 25, 2016, died in the Women's and Children's Hospital on Saturday as a result of the injuries that police allege were inflicted on her when she was just 41 days old.

Inspector Greg Hutchins said police were called to a Whyalla Stuart home after the SA Ambulance Service were told of an unresponsive baby at the address on June 5, 2016.

"(The little girl) was initially treated at the Whyalla Hospital and later was transferred to the Royal Adelaide Hospital for further treatment,” he said.

"She suffered a severe brain injury and has been in full-time medical care since."

A police investigation last year led to a 27-year-old man being charged with aggravated assault causing serious harm, aggravated assault causing harm and criminal neglect while a 23-year-old woman was charged with criminal neglect.

The charges were later withdrawn by the Director of Public Prosecutions.

Inspector Hutchins said on Wednesday the death of the little girl had been declared a major crime and consideration was being given to appropriate charges.

"This is a tragic case," he said.

"This little girl required 24-7 nursing care her entire life and today I'm appealing for anyone with information that could assist to come forward.

"To anyone who may have not told the truth in the past, anyone who might have thought that things were going to go away or get better, or anyone who just thought it was not their place to step up, I say 'now is the time'.

"Relationships may have been fractured within the family or among wider friends and today I urge those people to reflect on what has occurred and seek their cooperation.

"This little girl deserved better, and now deserves the truth.

"Police – particularly those in the Whyalla CIB [crime investigation branch] – have already put countless hours into this investigation, and will continue to work on this case until there is some sense of justice for (the little girl)."