Former “Smallville” cast member Allison Mack used her fame to lure women into the NXIVM sex cult for the group’s leader Keith Raniere, a former member testified in court on Monday.

The witness, a 31-year-old woman identified only as “Nicole,” said she met Mack in 2014 when she was struggling to make a living as an actress in Los Angeles, according to CNN.

Nicole’s boyfriend at the time suggested she take a program of courses offered by NXIVM in upstate New York that combined acting and psychology to reduce the fears she felt when auditioning, she told the court.

Nicole was uncomfortable with the way members idolized Raniere, she said, but she stuck with the program and even began teaching classes to make money.

In February 2016, Nicole said, Mack invited her to join “the Vow,” an all-women’s mentoring group within NXIVM where the members rigorously pushed each other in the name of self-improvement.

“She told me about this women’s organization,” Nicole testified. “That it was gonna make me feel better. It would be exactly what would help me get out of where I was mentally right then.”

Nicole said Mack told her that in order to learn about the group, she’d need “collateral” ― the group’s term for damaging information that could be used against Nicole if she ever left.

Nicole said Mack convinced her to write a letter falsely accusing her father of sexually abusing her.

She was also made to sign a variety of documents, including non-compete contracts, papers releasing NXIVM from liability for “physical and psychological injuries” and “disfigurement,” and an agreement allowing Raniere to take credit for anything she published, according to the New York Post.

After Nicole signed all the papers, she said, Mack told her “the Vow” would be a lifetime commitment and she’d have to be branded.

She said Mack told her they were now in a master-slave relationship, and that Nicole was forbidden to sleep with her then-boyfriend and was to remain celibate for three months.

“[Mack] said that she couldn’t let me out no matter how hard I cried because it would show me that if I cried hard enough, I could get out of anything,” she testified.

During her testimony on Friday, Nicole said Mack brought her to Albany to be near Raniere and to tell him she would do anything he asked, according to The New York Times. Nicole said Mack then told her, “Now go be a good slave.”

The next day, she said, Raniere blindfolded her and took her to a house where she was ordered to disrobe.

Nicole testified that Raniere tied her wrists and ankles to a table and started asking questions about her sexual past. She said that a third person, who she later learned was female, began performing oral sex on her.

“I was so confused,” Nicole told the court. “It’s terrifying.”

Raniere, 58, is currently on trial for racketeering and sex trafficking, as well as conspiracy, identity theft, extortion, forced labor, money laundering and wire fraud.

He has pleaded not guilty to the charges, but Mack, 36, pleaded guilty in April to two federal counts of racketeering and racketeering conspiracy.