Sarah Edmondson has played dozens of parts in her 20-year career in TV and film. But the Vancouver-based actor’s latest role, helping to bring down a notorious cult leader she once supported, may be her most important.

"It’s his karma, considering how he enslaved others for years, now he's in prison," said Edmondson, who’s written a book about her ordeal. "I just think it’s very poetic."

She started recruiting for NXIVM, a self-help program founded by a man named Keith Raniere, in 2005. "Looking back it's absolutely incredibly embarrassing to see how many red flags that were dismissed," said Edmondson. "Him being surrounded all the time by women who were serving him, driving him around, making him breakfast."

Edmondson says she had no idea Raniere was keeping some female NXIVM members as sex slaves. "For 99 per cent of the people involved it was not a sex cult, or it was and they kept it from us, which is sort of what we discovered with the trial."

Raniere was criminally charged after Edmondson turned him in to the FBI in November 2017. The final straw was being branded with a logo that turned out to be Raniere’s initials, and those of fellow actor and NXIVM recruiter Allison Mack. Edmondson talked about the branding with Dr. Oz on his syndicated talk show Tuesday afternoon.

“So when I saw that, my whole world collapsed. Because that was the moment I knew how messed up this whole thing was, and that I had Keith Raniere's initials on my body,” Edmondson recounted on the talk show. She decided to leave NXIVM and expose the group’s practices. This past June, Raniere was convicted of seven charges including sex trafficking, and could face life in prison.

In Edmondson’s new book, “Scarred,” she recounts her break with NXIVM and the guilt she feels for recruiting some of her Vancouver friends. "I'm incredibly sorry to them," she told Dr. Oz. "“I led them astray, I led them into something not only bad, but the complete opposite of what we thought they were doing."

Edmondson isn’t sure if she’ll keep acting, or begin working with cult victims to help others break free. "That’s more interesting to me, but who knows. My life’s been a rollercoaster and I’m just trying to go with it and do the best I can."