A “slapping therapist” who told parents to stop giving their diabetic son insulin has been jailed for at least seven years and six months for manslaughter.

Hong Chi Xiao, 56, was found guilty in October of manslaughter for breaching the duty of care he owed the six-year-old boy through gross negligence.

The boy’s last insulin injection to treat his type 1 diabetes came on the first day of a week-long “radical” Chinese slapping and stretching therapy workshop in Sydney in April 2015.

In the New South Wales district court on Friday, judge Garry Neilson jailed Xiao for 10 years with a non-parole period of seven years and six months.

The judge, who took five hours to deliver his sentencing remarks, said the boy’s parents were clearly led to believe their son would be cured of diabetes through participating in the workshop.