Camp Verde, Arizona (CNN) -- The owner of a retreat center testified at the manslaughter trial of self-help author James Ray Tuesday that she heard him tell participants of an ill-fated sweat lodge ceremony that he was God.
Ray is accused of manslaughter in the deaths of three people at his October 2009 "Spiritual Warrior" retreat in the desert. At least 15 others who took part in the ceremony became ill. More than 40 other people were uninjured.
Amayra Hamilton and her husband Michael own the Angel Valley Retreat Center where the lodge was located.
"I am the Alpha and the Omega. I am God," Hamilton recalled Ray said at the start of the ceremony. She testified she sat outside the sweat lodge and overheard him speak.
The ceremony consisted of eight rounds, with each round lasting 10 to 15 minutes. While they were not prevented from leaving, participants have said they were told to wait until the breaks between rounds.
Prosecutors have argued that the lodge -- made of willow trees and branches, and covered with tarpaulins and blankets -- was heated to a perilously high temperature, causing the participants to suffer dehydration and heatstroke.
Ray's attorneys have said the deaths were accidental and suggested that exposure to an unknown toxin in the lodge -- perhaps a pesticide, rat poison or something in the type of wood used to heat the rocks -- could have caused the fatalities.
Hamilton and her husband have filed a business claim tort suit against Ray for running his retreat, on their property, in what their attorney Kelley Ruda has called "a ridiculous manner."
The event participants paid up to $10,000 to seek "new areas of consciousness" at the retreat, according to testimony. Many had attended previous James Ray International seminars.