Read the moving letter director Paul Haggis sent Leah Remini after she left Scientology in 2013

In 2009, actress Leah Remini left the church of Scientology after 30 years and she didn't go quietly.

Remini explained her departure was because "no one is going to tell me how I need to think, no one is going to tell me who I can, and cannot, talk to."

One of the few celebrities who has been as vocal about breaking from Scientology is Oscar winning writer/director, Paul Haggis, who has publicly criticized the church for requiring members to "disconnect" from those who have chosen to cut ties with the religion.

In the wake of Remini's break from Scientology, Haggis wrote an open letter thanking the actress in The Hollywood Reporter. After Sunday's HBO premiere of explosive Scientology documentary "Going Clear" - in which Haggis is prominently featured as an interview subject - the letter is more relevant than ever.

While Haggis begins his note by cautioning, "Leah and I haven't spoken in quite a while" and "we were always friendly but never close friends," the director continues, "she called me as soon as she heard about my letter of resignation" from the church.

"Unlike the rest of my former friends, she expressed real sadness that I was leaving and concern for me and my family," Haggis writes.

So when he heard that Remini had later left the church, the "Crash" and "Million Dollar Baby" writer says "I read some things that really disturbed me."

"First was the way Leah was being attacked by her celebrity 'friends,' who were disparaging her character," he explains. "What was new to me was the report that Leah had run afoul of the church by challenging Scientology's leader, David Miscavige, who is held to be infallible."

Remini reportedly questioned the whereabouts of Miscavige's wife, Shelly, who hasn't been seen in years.

"The next thing I learned made me feel terrible," Haggis explains in his open letter. "Leah got in trouble because of me, because when I was 'declared' a 'Suppressive Person' and shunned, she came to my defense - without me ever knowing it. She had shouting matches with Tommy Davis, then the church spokesman, who had come to try and keep her quiet."

Haggis concludes by applauding Remini's bravery, writing:

I can't express how much I admire Leah. Her parents, family and close friends were almost all Scientologists; the stakes for her were so much higher than for me. Her decision to leave was so much braver...

I finally called Leah during the last week of July. Her answering service didn't recognize my number, so it took a while to get through. It was good to hear her voice and great to hear her laugh -- though it was easy to tell she had been terribly hurt and shaken by the events of the last weeks. That said, Leah is an incredibly strong woman and will get through this with the help of her family and her true friends. She is kind and generous and loyal; she has always cared more about others than herself. She barely knew me, and yet she fought for me and my family, a battle she had to know in her gut she was never going to win. That takes an enormous amount of integrity and compassion. I will leave it to you to decide if the same can be said of Scientology's executives and Leah's many former friends - especially those Scientologists who are watching her be smeared now and are choosing to stay silent.

I will forever be grateful to her.

To read Haggis' entire open letter on The Hollywood Reporter, click here.

After watching "Going Clear" Sunday night on HBO, Remini tweeted:

She later tweeted links to her posts on Instagram:

 

Instagram.com/LeahRemini

After watching the film, Remini gave an official quote to Scientology blogger Tony Ortega: "I wanted to thank the people who are in it and have worked so hard. You, Mike Rinder, Marty Rathbun, Marc Headley, Tom DeVocht, Lawrence Wright, Alex Gibney, and HBO. And Paul Haggis in particular for what he wrote on your website the other day. What Paul wrote is so exactly right."