Pulan Visaranai (English: Investigation) is a 1990 Tamil language film directed by R. K. Selvamani. The film features Vijayakanth in lead role. The film, produced by R.Sundar Raj and S.Raveendran,was a blockbuster and was remade in Hindi as Ravan Raaj: A True Story. The character of the antagonist Dharma (played by Anandaraj) is loosely based on the serial killer Auto Shankar.Telugu dubbed version "Police Adhikari" was also successful. Dharma (Anandaraj) is an auto driver who kidnaps young women and is on the payroll of a powerful politician R.R (Radha Ravi). "Honest" Raj (Vijayakanth), a DCP investigating the murder of an MLA, zeroes in on R.R but is suspended by his higher-ups due to political pressure. Few years later, he is brought back when Governor's rule is established and given charge of the investigation into the disappearance of a man whose sister had earlier disappeared. His investigation leads him to Dharma and R.R and then to a private hospital in Bombay.