Image copyright Reuters Image caption Nancy Salzman is set to be sentenced in July

The co-founder of a suspected US sex cult has pleaded guilty to committing racketeering offences.

Nancy Salzman, 65, told a court in New York she had stolen email addresses of critics of Nxivm group and tampered with video evidence.

Ms Salzman, known as Prefect in the group, is due to be sentenced in July.

Female recruits of Nxivm were allegedly branded with the initials of the group's spiritual leader Keith Raniere and coerced into having sex with him.

Investigators say the organisation is a sex-trafficking operation disguised as a mentoring group.

Keith Raniere himself was arrested by the FBI in Mexico last year. His defence team says the alleged sexual relationships were consensual.

In all, six people - including a liquor heiress and an actress - are facing criminal charges as part of an ongoing inquiry.

What is Nxivm?

On its website Nxivm (pronounced nexium) 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".

Image copyright Getty Images

Based in Albany, New York, the group was founded as Executive Success Programs in 1998 and says it has worked with more than 16,000 people.

Members of the group are reported to include the son of a former Mexican president and Hollywood actresses.

Federal prosecutors allege Mr Raniere oversaw 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".