In a deviation from bollywood traditions, the OST has been composed entirely by independent music artists. Early in 2014, Banerjee and his production team set out to find artists whose music would fit into the story of the film. After shortlisting about 200 songs from non-Bollywood artists across the country, the team began whittling the list down to a handful of songs and artists.
Aamir Khan was offered the villain's role in the film but declined it to take a role in Dhoom 3 (2013), another Yash Raj Films production.
Songs used in trailers are, 'Life is a Bitch' in the teaser and 'Chase in Chinatown' in the first trailer. Both feature in the movie's OST.
The writer of Byomkesh Bakshi novels was inspired by Sherlock Holmes of Sir Arthur Conan Doyle. Bakshi has a friend like Holmes has Dr. Watson. Style of storytelling also matches.
Rani Mukerji was the first choice for the role of Anguri Devi. The actress however balked at the character's risqué scenes and so Swastika Mukherjee (no relation) was cast instead.
The movie is based on stories of character Byomkesh Bakshi penned by Saradindu Bandopadhyay.