Actress admits manipulating women into becoming sex slaves for 'cult' leader

TV actress Allison Mack has pleaded guilty to charges that she manipulated women into becoming sex slaves for a cult-like group's spiritual leader.

Mack, 36, wept as she admitted her crimes and apologised to the women who prosecutors say were exploited by Keith Raniere and the purported self-help group called NXIVM, based in upstate New York.

"I believed Keith Raniere's intentions were to help people, and I was wrong," she told a judge in federal court in Brooklyn, New York City, as she pleaded guilty to racketeering.

Mack is best known for her role as a young Superman's close friend on the series Smallville.

After months of reflection since her arrest, she said: "I know I can and will be a better person." Her sentencing was set for September 11.

The plea means Mack will avoid going to trial with Raniere, wealthy heiress Clare Bronfman and another member of Raniere's inner circle, Kathy Russell. All have pleaded not guilty and denied any wrongdoing.

Potential jurors were expected to begin filling out questionnaires on Monday. Opening statements are scheduled for April 29.

The question of who jurors would see seated at the defence table had remained an open after new allegations that Raniere exploited a teenage girl.

His co-defendants have since sought separate trials and engaged in plea negotiations.

Court papers allege NXIVM formed a secret society of women who were branded with Raniere's initials and forced to have sex with him.

Defence lawyers have insisted any relationship between Raniere and the alleged victims, including an unidentified actress and other women expected to give evidence against him at trial, was consensual.

On Monday, Mack said that at Raniere's direction, she obtained compromising information and images of two unidentified women – called "collateral" within the group – that she threatened to make public if they did not perform "so-called acts of love".

The jury questionnaire covers several topics, including candidates' opinions about "rich individuals" and people who "engage in relationships with multiple sexual partners" and whether they "believe that people under the age of 17 should be able to consent to sex with adults".