40-year-old Clare Bronfman, an heiress to the Seagram liquor fortune, was reportedly among the most high-profile members of a cultlike organization in which some women were coerced into have sex with the leader. Her wealth helped finance the group, known as Nxivm according to her recent plea.

on Friday afternoon, Ms. Bronfman, pleaded guilty in Federal District Court in Brooklyn to charges arising from an indictment filed last year against her and several other followers of the group’s leader, Keith Raniere.

“I am truly remorseful,” Ms. Bronfman told Judge Nicholas G. Garaufis as she pleaded guilty to conspiring to conceal and harbor an undocumented immigrant for financial gain, and fraudulent use of identification. “I wanted to do good in the world.”

Nxivm billed itself as a self-help organization, offering workshops that promised self-fulfillment. Some women were recruited into a secret order within the group, branded on the pelvis with a symbol containing Mr. Raniere’s initials, and coerced into having sex with him.