A 71-year-old woman died after she stopped taking insulin at a workshop run by an alternative healer.
Danielle Carr-Gomm was left “howling in pain” before she died at Cleeve House in Seend, Wiltshire, where she was taking part in the event in October 2016.
The workshop promoted Paida Lajin therapy, where patients are slapped or slap themselves repeatedly.
Hongchi Xiao, of Cloudbreak, California, is on trial at Winchester Crown Court accused of the manslaughter by gross negligence of Ms Carr-Gomm, from Lewes, East Sussex.
He denies the charge.
Duncan Atkinson KC, prosecuting, told the jury Ms Carr-Gomm had sought alternatives to her insulin medication for Type 1 diabetes because of her vegetarianism and fear of needles.
Mr Atkinson said that the 30 people attending the workshop at Cleeve House were “keen disciples” of the defendant who was described as “Master Xiao” in the programme for the event.
He said those attending the workshop signed a disclaimer form which stated the practice was not “meant for medical treatment” and they fasted for several days, only consuming a Chinese tea.
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The prosecutor said Ms Carr-Gomm announced she had stopped taking her insulin on Monday 17 October which Xiao had “congratulated” her on.
Mr Atkinson described how one of the participants saw how Ms Carr-Gomm, by the Tuesday, “was vomiting”, and said on Wednesday Ms Carr-Gomm had not attended the workshop and was seen to be “vomiting, tired and weak”.
He added she was also “crying on her bed and howling in pain”.
‘Slapping’ heard coming from room
Mr Atkinson said her condition worsened in the early hours of the Thursday and she then died.
He added: “Whilst she was conscious, she could have received medical care, including the administration of insulin, and this would have saved her.
“No one was better placed than the defendant, the prosecution say, to make sure that this happened.”
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He said the sound of “Paida-like slapping” was heard coming from her room late on Wednesday while the defendant was with her.
Charles Row KC, defending Xiao, told the jury the defendant denied having a duty of care over Ms Carr-Gomm, who he had made “absolutely clear” to he was not medically trained.
He also told the court that Xiao had told Ms Carr-Comm not to suddenly stop taking her insulin and he had claimed that his actions were not causative of Ms Carr-Gomm’s death.
The trial continues.