Amazon's big-budget Lord of the Rings series will have to replace one of its lead actors.

Will Poulter, who joined the project in September, has had to drop out of the project due to scheduling conflicts. Sources tell The Hollywood Reporter his deal never officially closed, and his casting was never confirmed by the streamer. Amazon declined comment.

The nature of his role was being kept under wraps, but he was said to be playing a lead role in the show based on J.R.R. Tolkien's fantasy novels.

A search is ongoing to find another actor to replace the Midsommar and Black Mirror: Bandersnatch actor. The series' cast also includes Joseph Mawle (Game of Thrones), who is playing the central villain, Markella Kavenagh and Ema Horvath.

Production on the show is scheduled to begin next year in New Zealand, where Peter Jackson's LOTR film trilogy also filmed.

Amazon landed worldwide TV rights to Tolkien's work in 2017, with a multi-season commitment, with sources telling The Hollywood Reporter that rights alone cost as much as $250 million. Once production, casting and visual effects are factored in, the total price tag for the project could top $1 billion.

The series will be set in Middle-earth's Second Age, before the events of the films. J.D. Payne and Patrick McKay (Star Trek 4) are the showrunners. J.A. Bayona (Jurassic World: Fallen Kingdom) is set to direct the first two episodes and will executive produce, along with his producing partner Belén Atienza. Writers Gennifer Hutchison (Breaking Bad), Jason Cahill (The Sopranos) and Justin Doble (Stranger Things) are also EPs, as are Lindsey Weber (10 Cloverfield Lane), Bruce Richmond (Game of Thrones), Gene Kelly (Boardwalk Empire) and former Amazon head of genre Sharon Tal Yguado. Bryan Cogman (Game of Thrones) is a consulting producer on the series.

Variety first reported Poulter's departure.