US heiress Clare Bronfman has pleaded guilty to her role in an alleged sex trafficking operation.
Bronfman, the 40-year-old heir to the Seagram alcohol fortune, was accused of using more than $100m (£77m) to fund the suspected sex cult Nxivm.
She pleaded guilty on two counts - conspiracy to conceal and harbour illegal immigrants for financial gain, and fraudulent use of identification.
She told the court in Brooklyn that she was "truly remorseful".
"I wanted to do good in the world and help people," she added. "However, I have made mistakes."
Six people in total have been accused of being involved with Nxivm, pronounced nexium.
Bronfman is the fifth to plead guilty, with just one defendant - the suspected cult leader Keith Raniere - due to go on trial next month.
Bronfman will be sentenced on 25 July. She could face up to 25 years in prison, although sentencing guidelines suggest it could be up to only 27 months.
What is Nxivm?
Nxivm is a group that started in 1998 as a self-help programme and says it has worked with more than 16,000 people, including Smallville actress Allison Mack, who pleaded guilty earlier this month.
On its website, Nxivm describes itself as a "community guided by humanitarian principles that seek to empower people and answer important questions about what it means to be human".
Despite its tagline of "working to build a better world", its leader, Mr Raniere, stands accused of overseeing a "slave and master" system within the group.
According to the group's website, it has suspended enrolment and events because of the "extraordinary circumstances facing the company at this time".
Prosecutors allege the group mirrors a pyramid scheme, in which members paid thousands of dollars for courses to rise within its ranks.
How was Clare Bronfman involved?
Bronfman, a philanthropist and former showjumper, is the daughter of the late Canadian businessman Edgar Bronfman, whose net worth was estimated to be about $2.6bn (£2bn).
Bronfman was on Nxivm's executive board.
The millions of dollars she was accused of giving to the group were thought to have been used to pay for fake identities and court summons against perceived enemies.
Female recruits were also allegedly branded with Mr Raniere's initials and expected to have sex with him, as part of the system.
More on Nxivm:
Appearing at a court in Brooklyn, Bronfman admitted knowingly harbouring a woman brought to the US on a fake work visa in order to exploit her for labour.
As part of her plea, she agreed to forfeit $6m (£4.6m) and not to appeal any prison sentence of 27 months or less.
Mr Raniere, 58, was arrested in Mexico last year on sex trafficking charges, and is being held without bail.
He has pleaded not guilty to charges against him.
His defence team has argued that the alleged sexual relationships with women were consensual, and says he has denied child abuse charges against him.