Michael Roach and Christie McNally in 1996

A new investigation has been launched into an Arizona yoga retreat where tantric sex rituals and the death of an expelled member are raising questions once again.

The Daily Mail is reporting on the new investigation of Michael Roach's Diamond Mountain retreat, a Buddhist community whose members are said to have been involved in cult-like religious practices. One of its members, Ian Thorson, died of exposure and dehydration in a cave in the Arizona desert in 2012 after being expelled from the cult.

A recent episode of NBC's Dateline spoke with a former member of the cult and delved into the circumstances surrounding Thorson's death two years ago. Thorson's body was found in a cave alongside his wife, Christie McNally, the former wife of the cult's guru, Michael Roach, who was alive but described as "weak and delirious."

According to the former member, the cult is comprised of approximately 40 devotees of Tibetan Buddhists who are under the tutelage of Michael Roach. Adherents pledge to live at the Diamond Mountain retreat for three years, three months, and three days solely for the purpose of meditating. They are only permitted to communicate with pen and paper during that time.

Roach, whose unconventional practices have been condemned by the Dali Lama, is described as demanding total obedience from his followers - an obedience he does not demand of himself.

For instance, Buddhist monks, as he professes to be, are not permitted to marry or have sex with women. Roach secretly married cult member Christie McNally and later tried to justify it  with a bizarre explanation.

"He said that he had never had sex with a human woman," said former cult member Sid Johnson to Dateline, explaining that Roach told his followers that McNally was a supernatural being and not a woman.

During a three-year retreat in 1999, the two lived together in a yurt (a portable nomadic dwelling) but told retreatants they were celibate rather than admit they were married.

However, celibacy is not exactly possible in a cult that engages in tantric yoga.

As Roach himself admits, "We are not allowed to have sex, but in yoga there are practices that involve 'joining' with a partner," he said. "They are secret, and you are not allowed to disclose them. You might think of them as sex, but their purpose is to move inner energy. It takes very strict training."

Roach and McNally finally admitted to their marriage, but claimed they came from Christian backgrounds and wanted to honor that part of their religious heritage along with their Buddhist beliefs.

The marriage didn't last, however. In 2009, McNally left Roach for Thorson, a young student who had served as their attendant.

Roach said of the break up: "You should see your partner as an angel who came to teach you. I look at Christie that way - the education is finished and now she is teaching a new person. If you try to see it that way, it helps your heart to hurt less."

McNally's relationship with Thorson was stormy. She admitted during a lecture that he became violent and she stabbed him three times in the chest with a knife they had been given as a wedding present. Later, she claimed she was practicing martial arts and it went wrong.

After the incident, the couple was given five days to leave the cult, but they chose to leave immediately. Because they claimed they weren't ready to re-enter the world, they were planning on camping on land next to the retreat for a while.

At some point, the couple fell ill and McNally sent a distress signal to Diamond Mountain on April 22 from a transmitter she had been carrying. When cult members were unable to find them, they called police.

Police found Thorson in dead in a cave, having succumbed to dehydration. Next to him was McNally, who was weak and delirious, but alive.

As of this writing, a three-year retreat is still being conducted on Diamond Mountain and will not conclude until April 3, 2014. As the Mail reports, of the original 39 participants, 34 are still there.

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