Filming on the BBC and Masterpiece collaboration is currently underway. Julian Farino is directing from Stephen Butchard's script.
"We are thrilled such an array of talent have joined Benedict to create The Child in Time, our very first SunnyMarch production," David Boulter and Adam Ackland, executive producers for SunnyMarch TV, said in a joint statement.
"I'm so delighted to have such a talented cast join Benedict, Julian and the team and I'm very much looking forward to seeing them bring Stephen's script to screen," added Helen Gregory, executive producer for Pinewood Television.
The film follows a children's author two years after his daughter has gone missing.