US actress Allison Mack has found guilty to charges in an alleged sex trafficking operation disguised as a mentoring group.

Appearing in Brooklyn federal court, Mack pleaded guilty to racketeering and racketeering conspiracy charges linked to the suspected sex cult Nxivm.

In a statement,Mack accepted to recruiting women by telling them they were joining a female mentorship group.

“I must take full responsibility for my conduct”, she said.

Mack, known for the US television series Smallville, is one of six people facing criminal charges as part of an investigation into Nxivm.

Prosecutors allege the group mirrors a pyramid scheme, in which members paid thousands of dollars for courses to rise within its ranks.

Keith Raniere is alleged to be at the top of this structure as the only man, while Mack served as one of his top female deputies.

Female recruits were allegedly branded with Mr Raniere’s initials and expected to have sex with him, as part of a “slave and master system.”Allison Mack recruited women to join what was purported to be a female mentorship group that was, in fact, created and led by Keith Raniere,” Richard Donoghue, US attorney for the Eastern District in New York, said in a statement last year.

In court on Monday, Mack said she was instructed by Mr Raniere to collect compromising materials and images of two women within the group, threatening to make the photos public if they revealed information about the secret society.

“I believed Keith Raniere’s intentions were to help people”, Mack said in court on 8 April. “I was wrong.”

Mr Raniere was arrested by the FBI in Mexico last year. His defence team argued that the alleged sexual relationships were consensual.

Mack had previously pleaded not guilty in April 2018 to charges including sex trafficking, conspiracy to commit sex trafficking and forced labour.

She is now scheduled to be sentenced in September and will face a maximum sentence of 20 years in prison for each of the two charges.

Last month the co-founder of the group, Nancy Salzman, 65, also pleaded guilty to charges of racketeering. She is due to be sentenced in July.