Actress Allison Mack was arrested Friday by federal authorities on suspicion of sex trafficking in connection with the controversial self-help group Nxivm, which one former member has described as a “cult.”
A law enforcement source confirmed Mack’s arrest to PEOPLE.
The source says the allegations against Mack, 35, are connected to Nxivm, whose co-founder Keith Raniere was accused last month of sex trafficking and forced labor.
It was not immediately clear where Mack — best known for her years-long role as Chloe Sullivan on The WB’s Smallville — was taken into custody or where she was being held as of Friday afternoon.
She will appear in federal court in New York City later Friday, according to the law enforcement source. The details of the allegations against her were unavailable. She has not entered a plea.
A representative for Mack declined comment. It was unclear Friday if she has retained an attorney who could speak on her behalf.
In recent years Mack appeared in FX’s Wilfred and on The Following, on Fox, among other periodic TV roles.
She has previously discussed her connection with Raniere, the Nxivm co-founder. “Over the course of several years, Mr. Raniere mentored Allison in her study of acting and music,” her website states.
Raniere was arrested last month in Mexico on federal charges of sex trafficking and forced labor. He has not yet been arraigned or entered a plea.
Nxivm, which has not responded to numerous requests for comment from PEOPLE, soon after issued a statement in support of him, writing in part: “We are currently working with the authorities to demonstrate his innocence and true character.”
Formed in 2003, Nxivm is based out of Colonie, New York, and has been the subject of scrutiny from both law enforcement and journalists as it came under fire from Dynasty actreess Catherine Oxenberg, whose estranged daughter, India, joined the group in 2011.
Oxenberg, 56, first opened up to PEOPLE last year about how she believed India had been “brainwashed” by Nxivm.
In the fall, India posted on Facebook that she was “absolutely fine, great actually [and] I would never put myself or the people I love into any danger.”
For the past two decades, an estimated 16,000 people have paid as much as $3,400 for an executive coaching workshop offered by Nxivm, which promises to take participants on a journey of personal discovery and development, according to previous PEOPLE reports.
The criminal complaint against Raniere — known as “Vanguard” to his followers — alleged that he encouraged the formation of a secretive subgroup within Nxivm called “Dominus Obsequious Sororium,” (DOS) in which women were coerced into serving as sex slaves to their male masters.
The complaint, which was obtained by PEOPLE, outlines how authorities believe the women were forced to turn over “collateral” — identified as potentially-damaging personal information or materials, such as nude photographs, with which they later could be blackmailed.
The complaint further claims the women were branded with Raniere’s initials, as he “alone forms the top of the pyramid as the highest master.”
A cauterizing pen was used to make the permanent marks near each person’s pubic region, according to accusations in the complaint.
Federal officials likened Raniere’s group to a pyramid scheme, and the complaint claimed he exploited vulnerable women and profited from “independently wealthy women.”
If convicted on the sex-trafficking charges, Raniere faces a mandatory minimum of 15 years in prison.
In statements previously posted to Nxivm’s website, he said all involved in the subgroup were “consenting” adults. In the fall, the group denounced a New York Times article about them as “a criminal product of criminal minds.”
• With reporting by BRIANNE TRACY