Sir Lenny Henry, Maxim Baldry and Peter Mullan join cast of Amazon's Lord of the Rings series

The series, which is currently filming in New Zealand, is expected to follow characters that are mentioned in the extensive notes of Lord of the Rings' author J. R. R. Tolkein on Middle-Earth, with Robert Aramayo playing the lead character, Beldor.

Among the 20 new cast members announced today are Cynthia Addai-Robinson (Arrow), Kip Chapman (Top of the Lake), Trystan Gravelle (Mr Selfridge), Thusitha Jayasundera (Doctor Foster) and Lloyd Owen (Miss Potter).

They'll be joined by Peter Tait, who played Shagrat in the third film in Peter Jackson's film series – The Return of the King – however, it is currently unknown whether he will be reprising his previous role.

The rest of the cast includes Fabian McCallum (You, Me and the Apocalypse), Simon Merells (Legends of Tomorrow), Geoff Morrell (Top of the Lake), Augustus Prew (Kick-Ass 2), Benjamin Walker (Marvel's Jessica Jones), Sara Zwangobani (Home and Away) as well as Ian Blackburn, Anthony Crum, Maxine Cunliffe, Alex Tarrant and Leon Wadham.

Showrunners J.D. Payne and Patrick McKay said in a statement: "The world that J.R.R. Tolkien created is epic, diverse, and filled with heart."

"These extraordinarily talented performers, hailing from across the globe, represent the culmination of a multi-year search to find brilliant and unique artists to bring that world to life anew," they added. "The international cast of Amazon’s The Lord of the Rings series is more than just an ensemble. It is a family. We are thrilled to welcome each of them to Middle-earth."

The new series is set to explore new storylines within Tolkien's fantasy world, with original franchise star Orlando Bloom revealing in August that he spoke to one of the producers and can assure fans that "it's not a remake".

The Lord of the Rings TV series will be on Amazon Prime Video. If you’re looking for something else to watch, check out our TV Guide.