It was previously announced that BBC Four is planning to adapt Dirk Gently's Holistic Detective Agency as a one-off pilot.
Overman told SFX: "What I did was take the character, Dirk Gently, and his detection method, and write a new story."
He added that the pilot will contain "elements from the book" but explained that the original novel "isn’t really adaptable for TV".
The Misfits creator also admitted that the new version might not please fans of author Douglas Adams.
"I'm aware that it's a bit of a poison chalice," he said. "I am sure I will be hated...by the hardcore fans. I'm sure it will be quite controversial, but at the end of the day I have got to make it work as a TV show."