SEX cult actress Allison Mack breaks down in tears as she sings a bizarre love song for leader Keith Raniere on his birthday in this creepy video footage

The former Smallville star, who earlier this week pleaded guilty to her involvement in the sinister NXIVM group in which women were branded on their groins, can be seen teary-eyed and struggling to keep a hold of her emotions as she performs a version of "I Love You More Than You'll Ever Know" by Donny Hathaway.

Raniere, currently in jail facing a slew of federal charges including sex trafficking, can be seen in the audience watching the a cappella performance, which took place around the same time she began recruiting women for DOS - a secretive master-slave sect at the heart of NXIVM.

In the video, Mack is barefoot and wearing a loose white dress as she sings of her love for the cult leader with a group of backing singers.

The actress, currently facing up to 40 years in prison, then breaks down in tears as she sings: "I am only flesh and blood but I can be anything you demand."

Frank Parlato, who first published the video on his blog Frank Report, said the footage was taken around the same time that Mack began her "criminal behaviours".

I first saw this on 8chan.