A former lieutenant of the leader of NXIVM forced a young woman to stay in her bedroom for almost two years as punishment for expressing interest in another man and gaining weight, a federal court heard Tuesday.

Lauren Salzman testified that Keith Raniere “assigned” her to help a young Mexican member “learn from her mistakes” in solitary confinement or else she would be deported from the United States.

“Of all the things that I did in this case and all the crimes that I admitted to, this was the worst thing I did,” Saltzman said, holding back tears. “What can I say? I kept her in a room for two years and I didn’t go visit her. And when I did, I wasn’t even kind.”

Raniere, 58, is accused of running a secret sex-cult pyramid scheme that enslaved, manipulated, and branded women while promoting NXIVM as a self-improvement group. He has pleaded not guilty to charges of sex trafficking, racketeering conspiracy, child exploitation, and child pornography.

Saltzman, 42, previously testified she had been in a decade-long relationship with Raniere and was often manipulated with false promises of having children together. She is the daughter of NXIVM’s co-founder. After pleading guilty to racketeering charges in March, she became the first co-defendant to testify against Raniere.

Prosecutors said Daniela, who they only identified by her first name, and her family moved from Mexico to the U.S. around 2005 after hearing about Raniere and NXIVM. The family of six shared a two-bedroom condo in the NXIVM compound in Albany, New York and began to take the group’s self-help curriculum. Eventually, Daniela became an “integral part of the NXIVM community,” Salzman said.

In 2010, Salzman said Raniere told her about Daniela’s inability to lose weight and alleged she was stealing food from her family—and suggested that she seek “enlightenment” within the confines of her room in the condo. The family initially felt the measure was “extreme but it was a good option because they didn’t know how to handle her anymore,” Saltzman said.

“Keith told me that she was stealing and that she said she was going to lose weight and instead she gained 40 pounds,” Salzman said. “I felt like I had to take on the project because it felt like another test to prove I could be a good mother and help somebody.”

Salzman said she did not know it was Daniela’s request to see another man that prompted the punishment until after Raniere’s arrest.

After meeting with her parents, Daniela reluctantly agreed to go into her room until she came up with guidelines to fix what Raniere believed was “her problem behavior.” Raniere, however, wanted to make sure Daniela “didn’t view this as a vacation,” Saltzman said, and made her family remove everything except a mattress on the floor, a pen, and paper.

“I was told she had to go into her room to figure out how to fix what she did wrong,” Salzman said, adding that Daniela would not have any contact with her family even though they were in the same house. The only person allowed to speak with Daniela was Salzman.

“ Let me out. I'm coming undone. ” — Daniela, in a letter

One of Daniela’s sisters had a child with Raniere, and their youngest sister, Camila, is the alleged victim of Raniere’s child pornography charges.

“If she didn’t meet the conditions of satisfaction and left the room before Keith and I said she could, she would be sent back to Mexico. Then it became that if she went back to Mexico, she would lose her relationship with her family,” Salzman said.

Salzman said that she initially was told the discipline would be a weekend, with the possibility of extending it to a week if Daniela felt she needed more time. Salzman was told to look for “markers” in Daniela’s behavior that showed she was making progress and help her figure out guidelines in order to help her “grow from the experience.”

To show Raniere she was committed to being let out, Salzman said, Daniela would clean her room, exercise, and write letters to him every day. Raniere, however, insisted that all of Daniela’s attempts to leave the room were “game playing,” Saltzman said, and she was wasting everyone’s time.

“I felt like I was screwing this up and I began to see everything Daniela was doing as game playing instead of just her attempts to leave the room,” Saltzman said. “I was really mad at her for not figuring out what she needed to do to get out.”

Midway through Daniela’s captivity, Saltzman said she begged to be released. Daniela’s mother had also decided to go into the room next door in solidarity and remained there for over five months, according to Salzman. Salzman also said Raniere told her that Daniela would be “ethically obligated” to complete her guidelines knowing that her mother was going through “a similar tragic state.”

“Let me out. I'm coming undone,” Daniela allegedly wrote in a letter to Salzman, which was intercepted by her sister. Salzman said Raniere called the letter “a tantrum” to be ignored and was the first sign that the “project” was more sinister than initially proposed.

In 2012, Daniela decided to go back to Mexico rather than stay in the room, telling Salzman she would rather be without her family and Raniere than handle the solitude any longer.

Salzman said Daniela’s father and a fellow NXIVM member drove her to the Mexican border with little money, no documents to find a job, and strict orders to continue to write “book reports,” or summaries of books NXIVM members believed Raniere would enjoy to show their appreciation.

“All of our prescriptives were influenced by Keith’s perspective,” Salzman said. “We were incredibly abusive to Daniela. Everything she did we shot down. Nothing she could do was the right thing.”