A branch of notorious “sex cult” Nxivm — which has been known to brand female “slaves” with its founder’s initials — is covertly recruiting within the arty Brooklyn crowd.

While the Albany-based sect had seemed to be imploding after its founder, Keith Raniere, was arrested in Mexico last month on sex-trafficking charges, it now appears to be searching for new blood. Last month, a number of notable Williamsburg artists and writers, who asked not to be named, were invited by friends to what was billed as a party promising “authentic conversation” among creatives and “light vegetarian fare.”

A flyer for the event at a private home in Williamsburg billed it as “an evening of meeting cool, like-minded artists and chatting about life, authenticity, and the awesome human potential,” also vaguely referring to an unexplained “human expression program.”

But, once at the party, guests were shocked to be pitched a $10,000 “curriculum” called “the Source,” a supposed “life-improvement” program for actors and artists. One partygoer said the bash had started off fine — there had been no sign of sex, slaves or scalding irons — but things turned weird when the opening wine-and-cheese reception turned into a presentation pitch for the Source. The pitch sent some giggling guests inching toward the door, while others seemed to take it seriously. Of the friend who invited her to the soiree, the partygoer added, “She’s a nice girl, but now I’m kind of mad at her for trying to induct me into her sex cult.”

Closer investigation revealed the organizer of the Brooklyn bash is a current or former member of Nxivm. There is a video of Raniere discussing its principles with a devotee, “Smallville” actress Allison Mack, who was said to have been with Raniere when he was arrested. The Source appears to feed into and raise funds for Nxivm.

A criminal complaint filed against Raniere details a “secret sect” whose all-female “slave” members were obliged to have sex with their “master” Raniere and were branded with his initials like cattle.