Smallville actress Allison Mack flipped on NXIVM sex cult leader Keith Raniere, court documents reveal

NXIVM "slave master" Allison Mack turned on "Vanguard" Keith Raniere to help authorities convict the sex cult leader, according to new court documents.

The former Smallville star, who pleaded guilty to racketeering in 2019, was revealed as a key informant against Raniere in a pre-sentencing memo ahead of her next court appearance in New York.

The memo from federal prosecutors, first reported by Variety and subsequently obtained by multiple media outlets, argued for a reduced sentence due to Mack’s substantial cooperation prosecuting Raniere – including audio tapes proving he knew the so-called slaves were branded with his initials.

Mack faces between 14 to 17.5 years in prison for her role in the cult, and will be sentenced by District Court judge Nicholas G Garaufis on 30 June.

Acting US Attorney Jacquelyn M Kasulis and Assistant US Attorney Tanya Hajjar wrote to the court on Monday outlining Mack’s cooperation while also recognizing "the seriousness of the offence conduct in this case, which caused extraordinary harm and pain to the victims".

The memo detailed evidence provided by Mack to prosecutors that showed Raniere’s direction to the "DOS" slaves, as well as attempts to threaten victims by co-defendant Clare Bronfman, heir to the Seagrams empire.

Mack did not testify during Raniere’s trial, and her cooperation with prosecutors was previously unknown. But the results of her involvement were often unknowingly mentioned during the trial, including references to recordings of Raniere discussing how to brand members in the secret "Obedient Female Companions".

The transcript of the recording, included in the memo, showed Raniere and Mack discuss the branding ceremony for DOS "slaves" that he said should be filmed from different angles for "collateral", used to prevent the group’s members from leaving or discussing its secrets with outsiders.

"Do you think the person who’s being branded should be completely nude and sort of held to the table like a, sort of almost like a sacrifice? I don’t know if that, that’s a feeling of submission, you know," Raniere is quoted in the transcript.

"Laying on the back, legs slightly, or legs spread straight like, like feet, feet being held to the side of the table, hands probably above the head being held, almost like being tied down, like sacrificial, whatever," he added.

Raniere also told Mack the person should ask to be branded and call it an honour they want to wear for the rest of their life.

"And they should probably say that before they’re held down, so it doesn’t seem like they are being coerced," he said.

The memo said Mack met with prosecutors numerous times, and that she admitted to her own involvement in the secret society, according to Fox News.

"Allison Mack recruited her own ‘slaves’ by approaching young women and falsely describing DOS as a secret women’s empowerment group or sorority while intentionally concealing Raniere’s role in the organization," the memo said.

Lawyers for Mack are expected to file a sentencing memo by the end of the week.