Rachel McAdams felt "very privileged" to appear in 'Spotlight'.
The 37-year-old actress portrays investigative journalist Sacha Pfeiffer in the true-life drama and enjoyed spending time with the "incredibly awesome" writer as part of her research.
She said: "Sacha is just an incredibly awesome person. She works so hard and really cares about telling the story right, no matter what it takes.
"I feel very privileged to play her.
"I spent a lot of time with Sacha and her husband. They walked me around Boston, we had dinners together, they were on set and very much part of the project.
"I am so indebted to them. But all the reporters were incredibly generous and available."
The film chronicles how a group of Boston Globe reporters exposed a child abuse scandal in the Catholic Church and Rachel thinks it was an important story to tell on the big screen.
She told Britain's HELLO! magazine: "It's easy to forget these events and it's important we never do.
"Investigative reporting really is a dying art.
"These stories take years to bring together. They're not glamorous, they're just hard work."