Hongchi Xiao, who advocates the use of slapping and stretching to treat illnesses, says he was a Wall Street banker and wrote the script for the opening ceremony of the Beijing Olympics before developing his unusual medical technique based on ancient Taoist and Buddhist principles.

In the days before he died, Aidan Fenton, 7, is thought to have attended one of Mr Xiao's week-long alternative medicine workshops with his parents at a clinic in Hurstville.

Police and paramedics were called to the Ritz Hotel in Hurstville about 9pm on Monday to reports that the boy had collapsed and was not breathing.

His parents' screams alerted staff at the hotel, who called triple zero. A NSW Police spokesman said the boy died at the scene.

It is believed Aidan, from Prospect, had type 1 diabetes, and police are investigating whether he was no longer taking insulin before his death.

Mr Xiao's week-long Sydney workshop cost $1800 for participants to attend, and was held at the Pan Health Medical Centre.

Inspector Sean Daley, from Hurstville police, said the boy's parents had been interviewed, as had the medical practitioner. The Sydney workshop was Mr Xiao's last on his Australian tour, and he has since left the country.

St George police are investigating Aidan's death, with the assistance of the Homicide Squad. A NSW Police spokeswoman said this was standard practice for any unexplained death.

Mr Xiao's method includes practising paida - or slapping - and lajin - or stretching, a dual process that he says leads to self-healing.

In an interview last month with The Hindu newspaper in India, where he held a series of workshops, Mr Xiao said he had worked with many patients with all kinds of illnesses.

"After working with them, I learnt that diabetes, hypertension and many other problems got cured! They are indeed my teachers," he said.

He told the newspaper that repeatedly slapping one point of the body "builds heat, causing blood vessels to expand, and 'chi' to flow strongly. Yang rises, yin melts and long-held toxins and blocks are released".

In the interview, he said he was a banker who worked on Wall Street and in Hong Kong, before writing a "bestselling" book based on his life, as well as "the script for the opening ceremony of the Beijing Olympics". That information is repeated in several books he has written about paida lajin, a follower of Mr Xiao's methods claimed.

Mr Xiao said he learnt the process of slapping from a Taoist monk in the mountains of China, and together with stretching, the methods worked "to clear the meridians of blocks and help the body get rid of disease".

Australian man Ben James organised Mr Xiao's first tour of Australia in 2013, runs a Facebook page promoting paida lajin, and practises paida lajin daily.

He said he did not know the circumstances of Aidan's death, and could not comment specifically on the case, but offered his condolences to the family.

"I'm pretty shocked to hear about this happening, and my heartfelt condolences to the family for their loss," he said.

The 60-year-old, who lives in Queensland, said he first learnt of the practice of paida lajin by watching a YouTube clip about three years ago. He said stretching had helped alleviate the pain of a back injury he suffered while working as a roadie.

"It instantly relieved my back pain," he told Fairfax Media. "There's no doubt in my mind. I'm way more flexible now."

He also regularly practises slapping, and acknowledges some people may view it as odd.

"It is tough. It's not for everyone. It basically starts the circulation," he said, while saying that he did not fully understand the science behind it.

"The main points are the inside of elbows, backs of hands and feet, the reason being they are junctions where all the meridians go through. It unblocks any blockage in the meridians, and you get release."

Mr James said he understood the slapping and stretching were not intended to treat serious medical ailments.

"If you already have some medical issue or condition, you should take it to a doctor and get professional advice," he said.

"I would say it's more like a yoga teacher who shows you the positions, and you go home and do it at home.

"I'm passionate about this. It's also now why I'm so shocked about [the death of Aidan]," he said.

Tasly Healthpac Australia, the owner of Pan-Health Management Centre, said in a statement: "We are deeply saddened to learn the unexpected passing of this young boy.

"As a health care provider of more than 20 years history, we see every life as precious, especially those young ones. The loss is tragic and we wish to express our deepest condolences to the boy's family.

"From the information that we have, the boy was not a patient of Pan-Health and had not been treated by any of our doctors.

"Mr Hongchi Xiao rented a room from our centre to conduct what was described to us as a series of health seminars. The boy and his mother were participants in the seminar.

"We have been co-operating fully with police in their investigation of the case. We understand the Coroner's report is yet to be concluded.

"As the matter is now under investigation, we are not in a position to comment further."