Quebec provincial police have arrested three people in connection with the death of a woman in July 2011.

Chantal Lavigne, 35, died after taking part in a reported natural therapy treatment at Ferme Reine de la Paix in Durham-Sud, 110 kilometres northeast of Montreal. She was found wrapped in mud, cardboard and plastic.

Lavigne was taking part in a self-style group therapy called Dying in Consciousness (Radio-Canada)

Reports show that Lavigne was part of a self-improvement group practising risky therapy involving sweating and hyperventilation.

Radio-Canada's Enquête program which aired on Jan. 26 learned that Lavigne died from hyperthermia after undergoing a nine-hour session of intense sweating.

Gabrielle Fréchette, 53, of Victoriaville, Ginette Duclos, 61, of Saint Germain de Grantham and Gérald Fontaine, 39, of Danville have all been charged with negligence causing death and negligence causing injuries.

The three suspects appeared before a court in Drummondville Thursday.

"Dying in Consciousness"

Lavigne and several others were reportedly covered in mud and wrapped up for several hours. This was part of a seminar called "Dying in Consciousness" led by a self-styled Quebec therapist.

Lavigne and eight other participants were covered in mud, wrapped in plastic and blankets and spent nine hours lying with their heads in boxes while being encouraged to hyperventilate.

Gabrielle Fréchette, who directed the therapy said she was channelling Melchisedech, a figure mentioned in the Bible. (Radio-Canada)

Lavigne was eventually taken to hospital unconscious by ambulance, with a body temperature of 40.5 degrees. She died hours later.

Normal human body temperature is 37.0 degrees.

The Quebec coroner in charge of the case said she died of hyperthermia — a medical emergency caused by failed thermoregulation, when the body produces or absorbs more heat than it can dissipate.

Given the conditions, more people could have died "in cooking them like that" said Dr. Gilles Sainton. "It could have been much worse."

Claimed to be channeling biblical figure

The session was led by Gabrielle Fréchette, who has been offering self-improvement courses for 20 years, most recently at the Ferme Reine de la Paix, a country house near Drummondville.

She claimed to be channelling Melchisedech, a figure mentioned in the Bible.

According to Fréchette, about 2,000 people have taken her courses, including Lavigne, who completed 85 different sessions at the cost of more than $18,900.

The group's practices raise troubling questions, according to Dianne Casoni, a criminologist at the University of Montreal.

"How is it possible that groups that have so much influence over people and sometimes put them at risk are not more closely watched?" asked Casoni, who studies self-help groups.

"The problem with these groups is they're not overseen by any institution or government department."

Fréchette and her group continued to offer sessions after Lavigne's death, and told Radio-Canada's Enquête program that she was completely booked until the end of February 2012.

She also said she isn't responsible for Lavigne's death, and did her duty by calling 911.

At the time, Quebec provincial police, the Sûreté du Québec, said they were expecting to submit the results of their investigation into Lavigne's death to prosecutors.

Arrest mandates were given to the SQ before the arrests were made almost a year after Lavigne's death.