The role that Ajay Devgn ended up doing was first offered to Akshay Kumar who declined it due to the dark and violent tone of the film. Ajay Devgn subsequently did several movies with Prakash Jha including Apaharan, Rajneeti and Satyagraha.
The title of the movie (Gangaajal) means water of the sacred river Ganga in India. Water of the Ganges is supposed to be blessed and anyone who touches it gets cleansed of his/her sins. In the movie acid that is poured into the eyes of suspected criminals is called 'gangaajal' by the cops because they are supposedly cleansing the society.
The film won a national award in 2004 for its expose on social issues.
The film is loosely based on the 1980 Bhagalpur blindings. when police blinded 31 individuals under trial (or convicted criminals, according to some versions) by pouring acid into their eyes.
The film received a straight to DVD release in the international overseas market.