The child died at her family home in Rangeville, in southern Queensland, on January 7 after allegedly being “denied medical treatment for a period of approximately six days,” according to state police.
Emergency services were not contacted until about 5:30 p.m. on January 8, the day after her death, according to police.
It brings the total number of suspects charged with murder in the case to 14.
The girl’s parents — a 47-year-old woman and a 50-year-old man — were charged in January with “murder, torture and fail to comply with necessities of life,” according to Queensland police. Their most recent court appearance was in June.
Police allege that all 12 newly charged with murder were present during the period leading up to the girl’s death, and failed to seek medical assistance despite being aware she had an underlying health condition.
The 14 suspects, ranging in age from 19 to 65 years old, “made the choice to deny this young girl her right to medical care,” Regional Acting Superintendent Garry Watts said in the statement.
He added that the charges were the culmination of an “unprecedented” six-month police investigation.
The accused have been held in custody and are due to appear in court on July 6.