The grandmother of a six-year-old diabetic boy who died after being deprived of insulin and food in a Sydney "self-healing" course has been charged with manslaughter.
The 64-year-old woman, arrested on Tuesday, has become the third member of the same family arrested over the death.
Police last week charged the boy's father, 56, and mother, 41, with manslaughter after arresting them at their home in Prospect in Sydney's west.
The year 1 student, who cannot be named as an alleged victim of crime, attended the Tasly Healthpac medical centre in Hurstville in April 2015 for a week-long course with his parents.
Emergency services found him unconscious in a nearby hotel room, where he was staying, on April 28, 2015. He died at the scene.
Police will allege the parents and grandmother, who was looking after the boy before his death, were all "grossly negligent" in allowing the fasting and insulin deprivation during the $1800 course.
It was run by the self-described "healer" Hongchi Xiao, a Chinese-born man who continues to travel the world spruiking a therapy he calls paidalajin.
Paidalajin involves slapping the skin to the point of bruising, stretching and fasting to clear "meridians" in the body, allowing the dissolution of toxins, according to promoters.
"You have to be hard a little bit, cruel a little bit, but not too much," Mr Xiao said when describing paidalajin in a video last year.
Mr Xiao, who was allowed to leave Australia in the days after the boy's death, continued to promote his so-called therapy and was last year linked to the death of a diabetic British woman.
Danielle Carr-Gomm, 71, died during a weekend retreat run by Mr Xiao in south-west England last October.
He was arrested on suspicion of manslaughter, then released on bail and was originally due to appear again in January before the date was set back.
His blog has promoted recent courses with him in Hong Kong and one in Malaysia in late March.
The blog says paidalajin is not meant as a "substitute for medical care" but Mr Xiao elsewhere promotes it as such, deriding Western medicine.
After the Sydney boy's death, he denied responsibility on Facebook and posted a link to an Indian study purportedly showing improvements in diabetics after they went through paidalajin's fasting and "healing crisis".
The boy's parents were granted conditional bail after court appearances last week. They are due to appear before court on separate dates.
The grandmother, who appeared before Blacktown Local Court on Tuesday, was granted strict conditional bail. She is due to face Downing Centre Local Court on May 11.
All three face a maximum of 25 years' jail if convicted.