Leah Remini is the new QUEEN of the ex-Scientologists -- according to two famous defectors ... because she had the iron gonads to stand up to the Church.
As you know ... Leah filed a missing person's report with the LAPD ... claiming Shelly Miscavige, the wife of Scientology leader David Miscavige ... hadn't been seen for 6 years. Detectives found Shelly and determined she's fine.
Marc and Claire Headley -- two outspoken, former high-ranking Scientologists are praising Leah for her testicular fortitude. Claire tells us, "Shelly was seen for the first time in 7 years. At least we know she's alive."
Claire is skeptical that Shelly is exercising free will, and believes the outreach by Leah will show Shelly that people care about her "on the outside."
Marc believes Shelly was "trotted out" to LAPD officers by Scientology handlers, but a source connected to the Church tells TMZ that's ridiculous. The LAPD also tells TMZ ... they have concluded Shelly is not being held against her will.