The actress exposed the church's secrets and rituals in "Leah Remini: Scientology and the Aftermath", which debuted in America last year.
The programme featured allegations of abuse and detailed the reasons behind 10 former Scientologists' decision to defect, reported Rolling Stone.
Celebrating the second-season pick-up, Remini said, "It became clear to us that although we were telling painful stories of former members of the Church of Scientology, this show was resonating strongly with people everywhere.
The first series sparked a criminal investigation into "That '70s Show" actor Danny Masterson after a trio of women, inspired by Remini, came forward with sexual assault accusations against the actor, who is a Church of Scientology member.
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"Our intention is to send a clear message to abusers that they will not go unchecked and will not be permitted to continue harming people without being questioned and challenged," Remini continued.
Masterson has denied reports suggesting he is under investigation for raping fellow members of the Church of Scientology.