Keith Raniere, a self-improvement guru whose organization Nxivm attracted millionaires and actors, was sentenced on Tuesday to 120 years in prison on convictions that he turned some female followers into sex slaves branded with his initials.

US district Judge Nicholas Garaufis announced the lengthy term after hearing victims speak.

The court heard how Raniere bullied members of his cult-like group, where men were emotionally manipulated and women he chose as favorites were kept on starvation diets, branded and ordered to have sex with him.

He had been charged with sex trafficking and other crimes. At the sentencing hearing in Brooklyn, 15 former members of Nxivm spoke out against 60-year-old Raniere and the devastating impact he had had on their lives.

Raniere was also fined $1.75m.

Garaufis called Raniere “ruthless and unyielding” in crimes that were “particularly egregious” because he targeted young girls and young women.

Earlier, the first to give a victim statement was a woman identified as Camila who said she was sexually abused by Raniere on 18 September 2005 when she was 15, the New York Times reported. At the time, he was 46.

The court proceeding came after several years of revelations about Nxivm, which charged thousands of dollars for invitation-only self-improvement courses at its headquarters near Albany, New York, and branches in Mexico and Canada. Guests included Hollywood actors and other prominent individuals, some of whom were willing to endure humiliation and pledge obedience for Raniere’s vision of how to pursue perfection.

Nxivm has been the subject of two TV documentary series this year, HBO’s The Vow, and the Starz series Seduced: Inside the Nxivm Cult.

Prosecutors said Raniere led what amounted to a criminal enterprise, inducing shame and guilt to influence and control co-conspirators who helped recruit and groom his sexual partners. They said that among other crimes, Raniere began a sexual relationship in 2005 with a 15-year-old girl.

In court, the woman identified as Camila reportedly said Raniere forced her to recognise the date of her first abuse as their anniversary and that a 12-year relationship followed, during which he repeatedly sexually abused her and took naked pictures. She told the hearing she attempted suicide once and had an abortion “at his direction”.

He “damaged me in so many ways”, she reportedly said.

“He wanted me to believe that my only value came from how he felt about me. It has taken a long time to process the trauma he caused.”

Prosecutors also said Raniere confined another teenager to a room for nearly two years.

The likelihood of leniency had seemed to dissipate with the recent sentencing of Clare Bronfman, 41, an heiress to the Seagram liquor fortune, for her role in what has been described by some ex-members as a cult. Bronfman was sentenced to nearly seven years in prison. Prosecutors only sought five. Ex-followers told the judge Bronfman for years had used her wealth to try to silence Nxivm defectors.

Raniere’s followers called him “Vanguard”. To honor him, the group formed a secret sorority of female “slaves” who were branded with his initials and ordered to have sex with him, the prosecutors said. Women were also pressured into giving up embarrassing information about themselves that could be used against them if they left the group.

Along with Bronfman, Raniere’s teachings won him the devotion of Hollywood actors including Allison Mack of TV’s Smallville. Mack also has pleaded guilty and is awaiting sentencing.

In a sentencing submission, lawyers for Raniere said he “continues to assert his complete innocence to these charges”. They wrote that his jury conviction at an unfair trial resulted from a media campaign involving witnesses who were motivated to testify falsely as part of a “heavy-handed prosecution that threatened potential defense witnesses”.

And they noted that prosecutors have criticized him for not showing remorse as he tried to create a podcast to amplify his claims of innocence.

On Tuesday, Raniere said: “I do believe I am innocent of the charges. ... It is true I am not remorseful of the crimes I do not believe I committed at all.”

Prosecutors had sought life in prison while defense lawyers said he should face no more than 15 years behind bars.