Smallville actress Allison Mack, 38, is heading to federal prison for three years for her participation in racketeering and conspiracy in the cult group Nxivm. She had originally faced sentencing of up to forty years in prison.

US District Judge Nicholas G. Garaufis sentenced Mack to three years in prison on Monday, adding in a $20,000 fine, three additional years of supervised release, and community service.

In court, Judge Garaufis said she can remain under house arrest until September 29, when she must report to prison. The judge told the court her three-year sentence took into consideration that she had no prior criminal record and cooperated with prosecutors in the case.

However, the judge noted, "Your contrition and ownership of your actions can't repair the damage."

Mack, famous for her role in the TV series hit Smallville, pleaded guilty to the conspiracy charges in April and was sentenced on June 30.

Mack was a top leader and recruiter in Nxivm, a group often called a cult, that promised participants personal empowerment and happiness. Mack held her leadership position in a secret sub-group of Nxivm, DOS, which prosecutors said was an acronym for a Latin phrase meaning "Lord/Master of the Obedient Female Companions."

Mack recruited female slaves from the general Nxivm group to DOS, demanding proof of their commitment to the group via naked photos or secret assets or information. These assets were ordered by Mack so that the all-female slaves would not leave DOS.

Victims testified collateral also included falsified letters, such as one victim who wrote a fake letter saying her father had sexually abused her.

Victims testified they were sexually abused in DOS. On Monday, two women told the court about their abusive experiences, with one victim saying Mack is a "danger to living beings."

Numerous accounts of sexual abuse, women forcefully trapped against their will, and more shocking incidents were exposed in the hit HBO documentary "The Vow" in 2020.

Mack told the court on Monday she is extremely sorry for her actions and feels deep regret. She also said she too is a victim of Nxivm founder Keith Raniere.

"I fulfilled his every request, and made choices I will forever regret," she said, referring to Nxivm founder Raniere.

United States Attorney Jacquelyn M. Kasulis said, "Although Mack could have provided even more substantial assistance had she made the decision to cooperate earlier, Mack provided significant, detailed and highly corroborated information which assisted the government in its prosecution."

Mack shared a letter with the court, saying, "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. I am sorry that I encouraged you to use your resources to participate in something that was ultimately so ugly."

Nxivm was the brainchild of now-convicted felon Keith Raniere, who founded the organization. Well-known business leaders, celebrities, and others joined Nxivm from 2003 until 2018 when it was shuttered after authorities arrested Raniere.

In 2020, Raniere was sentenced to 120 years in prison for numerous crimes, including sex trafficking and racketeering he committed in Nxivm.