Allison Mack gave prosecutors tape of Nxivm leader talking about branding members

Nxivm sex-cult “slave master” Allison Mack helped federal prosecutors bolster their case against Keith Raniere by providing them with an audio recording of the leader talking about branding the group’s members, a new report said.

Mack’s cooperation was revealed in a sentencing memo filed by prosecutors on Monday where they ask Brooklyn federal judge Nicholas Garaufis to give the 38-year-old former “Smallville’’ TV actress a reduced sentence in return for her speaking up, according to Variety.com. “Although Mack could have provided even more substantial assistance had she made the decision to cooperate earlier, Mack provided significant, detailed and highly corroborated information which assisted the government in its prosecution,” prosecutors said in the memo obtained by the outlet.