Screenwriter Roth has revealed he and Leo butted heads as he was crafting the script because the Oscar-winning "The Revenant" star didn't like everything he read.
"I spent four or five years on this book, Killers of the Flower Moon, which everybody should read. It's a wonderful book," Eric told IndieWire. "My screenplay, I think, was accurate to the book."
"It's the story of Osage Indians, 1921, the poorest people in America who discover oil in this terrible land in Oklahoma, where they've been driven to. Then every killer in America comes to kill 184 of them for their money, but this really heroic guy comes in (to help)."
"That's supposed to start filming in March once the COVID clears out... They'll be continuing rewrites with that. Leonardo wanted some things changed that we argued about. He won half of them (arguments). I won half of them. So that's happening."
The film will also feature another Scorsese regular, Robert De Niro.
"When I read David Grann's book, I immediately started seeing it - the people, the settings, the action - and I knew that I had to make it into a movie. I'm so excited to be working with Eric Roth and reuniting with Leo DiCaprio to bring this truly unsettling American story to the screen," Scorsese previously said.
The director previously teamed up Leonardo DiCaprio on "Gangs of New York" (2002), "The Aviator" (2004), "The Departed" (2006), "Shutter Island" (2010) and most recently "The Wolf of Wall Street" (2013).