Filming has now begun on the Mammoth Screen-produced series, which as previously announced will co-star Tahar Rahim as Charles Sobrhaj, one of the most elusive criminals of the 20th century.
Jenna Coleman will play Marie-Andrée Leclerc, Sobhraj's partner and frequent accomplice, with Billy Howle and Ellie Bamber cast as Herman and Angela Knippenberg.
Charles Sobhraj (Rahim) was the chief suspect in the unsolved murders of up to 20 young Western travellers across India, Thailand and Nepal's 'Hippie Trail' in 1975 and 1976. Psychopath, con man, thief and master of disguise, having slipped repeatedly from the grasp of authorities worldwide, by 1976 serial killer Sobhraj was Interpol's most wanted man and had arrest warrants on three different continents.
When Herman Knippenberg (Howle), a junior diplomat at the Dutch Embassy in Bangkok, unwittingly walks into Sobhraj's intricate web of crime, he sets off an extraordinary chain of events that will see Knippenberg seek to bring Sobhraj to justice for his terrible crimes.
On joining The Serpent, Jenna Coleman says: "The Serpent intoxicated me into the dark seductive world of Charles Sobhraj. I'm so looking forward to delving into hippie trail depths and bringing to life this unfathomable real life story alongside Tahar, Billy, Ellie, Tom, Richard and the wonderful cast and production team for the BBC and Netflix."
Billy Howle says: "When I heard about the story behind The Serpent, I couldn't believe what I was reading. What an interesting role, in a fascinating story, with a brilliant team behind it - shooting in such a great part of the world, as well. I feel really fortunate to be a part of this project."