Disney, the founder of the animated studio, spent 14 years trying to persuade 'Mary Poppins' author P L Travers to allow the studio to make a film based on her popular children's story.
Travers was reluctant to sell the film rights but Disney eventually won her over. Travers, however, did not like the film and became so upset with Disney that she never worked with him again.
The film will see 56-year-old Hanks opposite actress Emma Thompson, who plays Travers, reported E! Online.
"I don't want to upset anybody off. I want to be accurate, more than anything else. John Lee Hancock is the director, and it's really the story of Emma Thompson more than it's about me, so, you know, I don't want to screw up," he said.
The "Da Vinci Code" star also said that he did as much research as possible because he did not want to disappoint Disney's die-hard fans.
"I went up to the Disney Family Museum at the Presidio in San Francisco (California). At first, I just went up to meet Diane Disney, who is Walt's daughter, and some of the staff up there, but then they invited me back up again on a day it was closed.
"They just opened up all the exhibits for me, and I saw every piece of film and heard every piece of audio. I also have like 39 hours of informal interviews. It's one thing to see him when he talks on TV but another thing to get him when he's just having a conversation," Hanks said.
"He's a fascinating guy, because what we have is this benevolent animator who would introduce us to his cartoon characters. But what he was was very tough, competitive and a very loyal businessman that invented an art form that is still going great guns today," he added.
