New York (CNN) A former "master" in the secret society of women within the group known as Nxivm testified Monday that she began to grow concerned as she heard about acts of violence against the women involved, including plans for a sex dungeon -- all allegedly directed by Nxivm founder Keith Raniere.

The secret sex cult, known as DOS, was made up of women who were either "masters" or "slaves" and Raniere was the leader, despite the fact that it was meant to be a women's empowerment group, jurors in Brooklyn heard.

Lauren Salzman, 42, who pleaded guilty in federal court to charges of racketeering and racketeering conspiracy in March, testified she was a master and had six slaves of her own. She was told that the group would teach women to be "master of your own life."

At meetings in their "sorority house," Salzman and other masters would administer paddlings with leather belts. Raniere would call in to check how they were going, she testified.

"He called in and wanted to make sure we were flicking our wrists hard enough," Salzman testified.

Salzman, an inner circle member of Nxivm who said she was Raniere's slave, testified she heard from another DOS member that Raniere had paddled her and kicked her.

"These things started to become scary for me," Salzman said.

Raniere has been charged with racketeering, sex trafficking, sexual exploitation of children and human trafficking, among other offenses. He has been held in federal custody in Brooklyn since his arrest in Mexico in March 2018.

He pleaded not guilty to all charges. His attorney has argued Raniere's relationships with Nxivm followers were consensual.

A 'lifetime vow of obedience'

Salzman had been a part of Nxivm (pronounced "NEX-ee-um") for 20 years, even serving on its executive board, and had a romantic relationship with Raniere, she told the jury.

She was recruited to DOS in 2017, years after their romantic relationship ended. She had to give the woman who recruited her collateral -- information that was so damaging that Salzman would rather die than to have it released -- to ensure she wouldn't share information about the group, she testified.

At first, Salzman detailed how she and her mother, Nancy, had allegedly worked with Raniere and others to give a woman Valium against her will, after the woman began acting erratically at a Nxivm event.

Salzman testified that Raniere wanted the woman to be able to sleep, so Salzman's mother tried to give her the drug, and men eventually had to hold the woman down and force a pill into her mouth. Valium was crushed and put in scrambled eggs to feed the woman, Salzman said.

That piece of collateral was rejected because it included compromising information about Raniere. Salzman was instead told by the woman who recruited her to send in nude photos of herself, she testified. Once she was in the society, Salzman found out she would report directly to Raniere as a "first line" master.

"This is a lifetime vow of obedience," Salzman testified she was told. "(Raniere) would be my master and I would be his slave."

Within a few days of being accepted into the group, Salzman, like other members, was branded near her bikini line with what were Raniere's initials, unbeknownst to many of the women who were ceremonially branded.

The women were expected to wear a "collar" -- a piece of jewelry they couldn't take off that symbolized their commitment to their master, Salzman testified.

She initially thought the concept of branding was created by the women in the group, but another member told her otherwise.

"None of us would have come up with the idea that we'd brand ourselves," Salzman testified that another DOS member told her. "That was Keith's idea."

Marc Agnifilo, Raniere's attorney, previously told CNN that Raniere believed DOS was a "pro-woman group."

"He created it to have women have their own society ... where men would play no role," Agnifilo said.

'At the time, I thought it was consensual'

Shortly after her own branding, Salzman said, she gathered six women she'd recruited as her own slaves and had a ceremony for them. The first to be branded writhed in pain, Salzman testified.

"She was squealing and screaming and it looked horrendous," Salzman said. "It scared the other girls."

Salzman said that at the time her slaves were branded, she thought that the women could have opted out of the ceremony. But today, she feels differently and doesn't believe it was right to brand Raniere's initials on women without them realizing it.

"Ultimately, they were my slaves and they were under a collateralized vow of obedience," Salzman testified. "At the time, I thought it was consensual."

Among the pieces of collateral that Salzman's slaves gave to her, she testified, were nude photographs, videos with disparaging comments slaves made about family members, access to bank accounts and permission to gain possession of property such as cars and other personal belongings.

"If I wanted to take the property, I could have taken the property," Salzman testified.

Nxivm operated like a multilevel marketing scheme, pushing members to take classes that cost as much as $5,000, according to court records.

It encouraged members to take more classes to move up the ranks and to recruit other members to help create more revenue, which left some members in debt to Nxivm itself, according to an affidavit by the FBI.

Witness says she helped in extortion efforts

Salzman's mother, Nancy, pleaded guilty to racketeering conspiracy before the trial began.

Lauren Salzman testified that she and others, including Raniere, kept a woman in a room for two years, and that she and others within DOS, including Raniere, took property and extorted more property from women within the group.

For about six weeks after the women were branded, they were told to send photos of their brands healing every day to Salzman, she said.

Salzman said she became concerned when she learned that Raniere wanted to make a "dungeon" in the basement of the DOS sorority house. She testified that the dungeon would have a cage where someone could be placed if they were "most committed to their growth" -- where women could be locked in and not know how long they would be kept there.

A DOS master was working with Raniere in 2017 to order items for the dungeon, Salzman testified, including handcuffs, wrist and ankle ties and nipple clamps — but ultimately the order was canceled after a bombshell New York Times report exposed claims from former DOS slaves. The dungeon was never built.