Allison Mack said she was "sorry" in a letter filed in court ahead of her June 30 sentencing. for her role in Keith Raniere's NXIVM organization.

The former "Smallville" actress called Raniere "twisted" in the letter which was filed in Brooklyn Federal Court per the New York Post.

She said following Raniere was "the biggest mistake and greatest regret of my life."

"I am sorry to those of you that I brought into Nxivm. I am sorry I ever exposed you to the nefarious and emotionally abusive schemes of a twisted man."

ALLISON MACK PROVIDED GOVERNMENT AUDIO RECORDING OF NXIVM LEADER KEITH RANIERE DISCUSSING 'BRANDING' RITUAL

Mack pleaded guilty in 2019 to racketeering conspiracy. The applicable advisory Guidelines range for her crimes is 168 to 210 months behind bars.

In this Dec. 6, 2018, file photo, television actress Allison Mack leaves federal court in New York.  (AP Photo/Seth Wenig)

"It is now of paramount importance to me to say, from the bottom of my heart, I am so sorry… I threw myself into the teachings of Keith Rainire [sic] with everything I had," she wrote in the letter.

She also acknowledged her friends who "fought hard to show me the truth about Nxivm and Keith."

"I pushed you away and silenced myself toward you when you were trying to save my life. … I lied to you, again and again, in order to protect the delusion I was so deeply committed to believing."

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"The list of those harmed by the collateral damage of my destructive choices continues to grow as I become more and more aware of how my choices have affected those around me," she wrote. "I am grateful that I have made it through this process alive and that I stopped when I was."

The 38-year-old, who has been under home confinement, was involved as a master to recruit women as "slaves," new court documents showed last week.

In the June 21 memo obtained by Fox News, Acting U.S. Attorney Jacquelyn M. Kasulis and Assistant U.S. Attorney Tanya Hajjar spell out the wealth of information Mack provided to prosecutors a month before the 2019 NXIVM trial was scheduled to take place. According to the U.S. attorneys, Mack detailed Raniere's assignments for DOS "slaves," the disgraced NXIVM leader's use of "demeaning and derogatory language," co-defendants Clare Bronfman's "attempts to harass and threaten DOS victims," and more.

The former ‘Smallville’ star will be sentenced at a hearing on June 30. (Jemal Countess/Getty Images)

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But the most pivotal was a recording of a conversation between Raniere and Mack that prosecutors say "served as crucial evidence of Raniere's role in devising the branding ceremony in which DOS ‘slaves’ were branded with a symbol, that unknown to them, represented Raniere's own initials."

The memo includes a transcript of the conversation in which Raniere asks Mack's opinion of holding a DOS "slave" to a table "completely nude…sort of almost like a sacrifice?" to which the former actress responded, "Yea."

Raniere also offered up the idea to Mack to videotape the branding ritual "from different angles," and suggested "it probably should be a more vulnerable position type of a thing" with the females "laying on the back, legs slightly, or legs spread straight, like feet, feet being held to the side of the table."

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Raniere also instructed Mack to ensure the girls "ask to be branded" beforehand "so it doesn't seem like they are being coerced."

The government informed the court that Mack's recording "provided critical evidence of Raniere's role in DOS" and his involvement in the branding ritual which he "repeatedly denied."

FILE - In this Tuesday, May 7, 2019 file courtroom drawing, defendant Keith Raniere, center, leader of the secretive group NXIVM, is seated between his attorneys during the first day of his sex trafficking trial. (Elizabeth Williams via AP, File)

The court docs confirm Mack met with the government "numerous times" at its request. In addition to providing evidence against her co-defendants, the attorneys say Mack also admitted to her own criminal involvement.

"As the Court is well aware, DOS was a secret organization led by Keith Raniere and comprised of ‘masters’ who recruited and commanded groups of ‘slaves.’ 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 government recalls in the memo.

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As a "master," Mack ordered "slaves" to provide collateral, which the government describes as "damaging confessions about themselves and loved ones (truthful or not), rights to financial assets, and sexually explicit photographs and videos – to prevent them from leaving the group or disclosing its existence to others," it continues.

Mack's assistance in providing the government evidence for trial had not yet publicly been announced. The 38-year-old was scheduled a June 30 sentencing hearing in late May. The order says that "if necessary," the sentencing could overflow into July 1.

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At the time Mack's sentencing date was released, sources told Fox News they are "relieved" she will "finally" get time behind bars.