The NXIVM cult has held the public’s attention for its sensational inner workings – everything from branding women to sex trafficking and brainwashing – but a new documentary airing this weekend raises questions that are even more sinister: What really happened to four female members who died or disappeared?

‘I’ve had people killed because of my beliefs,’ Raniere says in a video clip included in the Investigation Discovery film The Lost Women of NXIVM.

Raniere, 59, will be sentenced next month on charges of trafficking and racketeering after being convicted earlier this year. Others from his inner circle – including Smallville actress Allison Mack and heiress Clare Bronfman – have also sensationally pleaded guilty to various NXIVM-related crimes.

But the new documentary airing this Sunday explores the mysterious deaths and disappearances of other women connected to Raniere. Kristin Snyder vanished in 2003 in Alaska after taking NXIVM courses and her death was presumed a suicide – but her body was never found.

Gina Hutchinson, who publicly accused Raniere of statutory rape, was discovered dead in Woodstock, New York in 2002 – but the alleged self-inflicted shotgun wound is re-examined in the film.

One of the cancer survivors was Kristin Keeffe, who is currently in hiding in Florida after Raniere fathered her son and she escaped NXIVM, becoming a primary whistleblower for authorities. She has never publicly shared her story until now

Barbara Jeske, 63, and Pamela Cafritz, 57, two of Raniere’s top lieutenants who had intimate knowledge of the group’s activities, were diagnosed with cancer and died while living with the manipulative cult leader. More women in his ‘harem’ also suffered from the disease. Could there have been a nefarious cause of those illnesses?

That’s what the documentary sets out to find, including exclusive interviews with former members who told their stories to filmmakers and investigators, keen to bravely step out of the shadows and expose the man branded a ‘pervert,’ ‘evil’ and a ‘psychopath’ by those interviewed for the program.

‘I couldn’t believe all the facets to the story,’ filmmaker Pat McGee tells DailyMail.com ‘I was just sitting there and my jaw dropped.’

The series follows investigator Frank Parlato – who worked as a consultant for NXIVM in 2007 before he raised questions about missing money and was fired – as he tries to discern the true stories behind the 2003 Alaska disappearance of Snyder; the 2002 suicide of Hutchinson; and the cancer deaths of Jeske and Cafritz.

Kristin Snyder vanished in 2003 in Alaska after taking NXIVM courses and her death was presumed a suicide – but her body was never found

Barbara Jeske, 63, and Pamela Cafritz, 57, two of Raniere’s top lieutenants who had intimate knowledge of the group’s activities, were diagnosed with cancer and died while living with the manipulative cult leader. More women in his ‘harem’ also suffered from the disease. Could there have been a nefarious cause of those illnesses?

Parlato talks to another former member who lived in the house with the cancer victims and Raniere; she declines to be identified, going so far as to demand voice modification while she shows the filmmakers around the home the cult leader and the women shared.

The anonymous woman also battled cancer, as did others in the home. She offers up a sample of her hair from the time of her sickness; an analysis in the film shows extraordinarily high levels of barium and bismuth – chemicals that could be found in items that include rat poison, according to an expert on the show.

One of the cancer survivors was Kristin Keeffe, who is currently in hiding in Florida after Raniere fathered her son and she escaped NXIVM, becoming a primary whistleblower for authorities. She has never publicly shared her story until now.

‘I was very determined, at a young age, to understand spirituality,’ she says in the film, explaining a belief shared by many lured into NXIVM by Raniere’s purported self-help philosophy. They believed, for years, that they were doing good and pursuing a different way of life under a charismatic leader.

‘I always thought that would be walking with God,’ she says. ‘I never thought that that might entail walking with the devil.’

Fiercely protective of her son – one of the only children born to Raniere, who allegedly forced abortions among the myriad followers he impregnated – Keeffe at one point walks off camera and ends the interview.

Gina Hutchinson, who publicly accused Raniere of statutory rape, was discovered dead in Woodstock, New York in 2002 – but the alleged self-inflicted shotgun wound is re-examined in the film

Gina Hutchinson's sister Heidi says in the film that her death was 'very suspicious'. She added: 'She was a very gentle soul. For her to even be that violent, to … choose a method that violent – that concerns me’

But she says: ‘I was involved in NXIVM for 16 years and Keith Raniere for 24 years, and I became the primary whistleblower. I left my house with nothing but my pocketbook, and I took a taxi to the police station – and while I was at the police station, the NXIVM attorneys found out and … called there and said: “We know she’s there.”

‘And I said: “That’s it. I can never go back.” I knew they would put millions of dollars into finding me, grabbing me, doing whatever they could to take my son. I knew that, when I walked into that police station, in Keith’s mind, that was nuclear war. No one had ever done anything like that to him before.

‘I knew I was being hunted like an animal.

‘Initially … everyone was against me. All the people that were against NXIVM were against me, and all the people that were in NXIVM or that knew about my departure were against me. And here I was coming with all this evidence and information … no one would help me.’

Smallville actress Allison Mack pleaded guilty to racketeering conspiracy and racketeering relating in relation to sex trafficking within NXIVM. She was accused of recruiting women to join what she told them was a self-help group

Keith Raniere, 59, will be sentenced next month on charges of trafficking and racketeering after being convicted earlier this year. He faces life in prison

She adds: ‘I decided it was time to leave the moment that I realized that Keith was a psychopath … he was absolutely deliberately trying to destroy people.’

One of the people who stepped up to help Keeffe was Parlato, he says; he housed her in a Florida apartment. He believes that’s one of the reasons she finally agreed to speak on camera.

But she’s not the only one coming forward for the first time.

Heidi Clifford, wife of Kristin Snyder, who disappeared in Alaska in February 2003 after several outbursts at NXIVM courses, also eventually agreed to speak to filmmakers.

Snyder, an environmental consultant originally from Kentucky, had become heavily involved in NXIVM courses and had even visited the cult’s headquarters in Albany – where Clifford and others interviewed in the film believe her relationship with Raniere took an even more nefarious turn.

Heiress Clare Bronfman pleaded guilty to NXIVM-related crimes earlier this year. She is seen leaving a Brooklyn federal court in April

Susan Dones, a former NXIVM member, tells Frank Parlato in the film: ‘Keith did not like women being lesbians. Being gay, period, was an act of defiance, especially if you’re a woman. It was an act of defiance and, I think for him, because he treated women as objects, if you’re a lesbian, then you’re not available to him'

‘My suspicion is that he might have even had sex with her,’ former NXIVM member Susan Dones says in the film, adding: ‘Keith did not like women being lesbians. Being gay, period, was an act of defiance, especially if you’re a woman. It was an act of defiance and, I think for him, because he treated women as objects, if you’re a lesbian, then you’re not available to him. So he could possibly try to turn her. It’s kind of like a notch on his belt.

‘If she was manipulated, somehow, into having some kind of sexual relationship with him … we know that this is a guy that will do evil things to women.’

Snyder disappeared in Alaska, prompting a search of the ironically named Resurrection Bay, after an outburst at NXIVM courses. That outburst involved multiple claims that she was pregnant by Raniere, says her wife, who was present during the courses at which Snyder had her outbursts.

The cult branded female followers with the initials of its leader, Keith Raniere

An IT security consultant in the film also alleges that NXIVM leaders knew Snyder was pregnant – ‘shedding new light’ on the mysterious disappearance, Parlato says.

Snyder’s wife of two years, Clifford – who finally agreed to go on camera – says in the film: ‘I never talked about it at all until today, and I’m still scared. I’ve ran the last 15, 16 years of my life, being scared of these people. I’m still scared.

‘I think Keith Raniere had inappropriate sex with her, which would have thrown her off her rocker … she reported to me that she was pregnant with Keith’s baby, and I’m like, “What? What are you talking about?” Then when I heard it more in the class, when she was yelling it out … they just kept pulling her out of the room. This is not just one time. This is three or four times, she was blurting this out.’

After that, Snyder disappeared. A kayak was discovered stolen and a suicide note was found in her car, but her body was never found – despite a comprehensive search by authorities and friends. The film interviews a handwriting expert who casts doubt on the authenticity or meaning of the note.

Her wife has a new outlook on the tragic disappearance following the revelations about NXIVM and Raniere over the past few years.

‘There’s so many layers to this,’ Clifford says in the film.

And it’s not the only case under serious scrutiny from Parlato and filmmakers in The Lost Women of NXIVM. The film also focuses on the 2002 death of Gina Hutchinson, whose body was found in Woodstock, New York, about an hour and a half from the cult’s Albany headquarters. The death was ruled a suicide, and she was presumed to have killed herself with a shotgun – but the film, using a female subject of similar build and consulting a ballistics expert, raises doubts as to how such a self-inflicted death could have even been physically possible.

Hutchinson was ‘always super intelligent, very sensitive,’ her sister says in the film. ‘She always brought in stray animals, was always very caring and compassionate. She was 33 when she died. It’s all very suspicious.

Kristin Snyder allegedly disappeared in Alaska's Resurrection Bay, revisited by Parlato; her body was never found and the film raises questions about whether she actually committed suicide

‘She was a very gentle soul. For her to even be that violent, to … choose a method that violent – that concerns me.’

Parlato, who comes across in the film as a hard-nosed personality with a single-minded agenda, tells DailyMail.com that he initially had though Hutchinson ‘was a suicide. Now I’m not convinced that she is.’

Like many of the NXIVM followers, he says, he initially had a positive impression of the group when he began consulting for them in 2007.

‘At first, everybody seemed like they were just a group of misunderstood people who were just trying to forge a life that was a little bit different than mainstream,’ he says. ‘It really wasn’t ‘til I discovered some financial improprieties I began to suspect that the group was possibly doing some illegal activities.’

Still, he admits: ‘I didn’t think it was going to wind up being’ in any way connected with deaths.

‘I believe once it airs, the authorities will sit up and take note,’ Parlato tells DailyMail.com, explaining his opposition to the group as a ‘dogfight’. ‘The end result being that … these assumptions [of causes of death] will be revisited.’

He says he’s looking into ‘several other curious cases where women were here and now they’re gone. We don’t know that something bad happened to them, but there’s a possibility that the number may be larger than four.’

Parlato consulted a ballistics expert and used a similarly-sized subject to recreate the 2002 alleged suicide of Gina Hutchinson - raising questions about whether she could have actually self-inflicted the shotgun wound that killed her

Parlato says that he couldn’t have found a ‘better partner’ than Investigation Discovery as the team followed him across the US and were ‘committed to actually doing an investigation.’

Filmmaker McGee agrees and hopes the revelatory documentary will capture the attention of viewers, help the participants and perhaps reach a wider net of people affected by the cult.

Parlato, McGee tells DailyMail.com, ‘has this determination to go to the ends of the earth. We’re in the [Florida] Keys, we’re in Alaska, we’re all over the country. He wants to go wherever the story takes him … he really wants to find out what happened. He has a lot of questions that he wants answered, and that may ruffle a lot of feathers. Some people may not like his direct attitude, but he’s on a quest to figure out what the truth is.’

Parlato and filmmakers traveled everywhere from upstate New York to Texas and Alaska to search for answers in the deaths and disappearances of NXIVM members

The most important part of the project, though, McGee says, was the story that the victims had to tell.

‘We’re giving them the tools; we’re trying to give them the opportunity to get their story out,’ he tells DailyMail.com.

He adds: ‘Heidi is very brave, in my opinion – and I think she was terrified for years to ever speak about NXIVM, to ever speak about Keith Raniere. She’s felt threatened her whole life since the disappearance or death of Kristin Snyder … it was a big moment for her. She had the courage to step away from being … hidden and come forward, and I think it was a life-changing moment for her.

‘I think at this point she said: “Look, I’m sick of being terrified, I’m done with Keith and NXIVM, I’m not going to be scared any more.”

‘Kristin Keeffe, you know, she’s in an undisclosed location, hiding. She’s on the run. She doesn’t want to be in the public – and for her to sit down and share her story … was amazing.

‘I’m just grateful to be part of this great group of storytellers and get the opportunity to tell the story of survivors of NXIVM. I think there’s a lot we know now about Keith Raniere that people did not know.

‘It’s fair for Frank Parlato to ask tough questions about some of this stuff. I think it’s fair for him to go out to talk to victims and survivors and witnesses and to kind of make sure these women did not die in vain.’

The Lost Women of NXIVM airs on Sunday, December 8 on Investigation Discovery at 9/8c. It will also air December 21 in the UK on Quest Red