The son of Chandi Prasad Singh, an erstwhile Indian prince and a prominent criminal lawyer, K.N.
He was selected to represent India in the 1936 Berlin Olympics before circumstances compelled him to go to Calcutta to attend on his ailing sister.
There he met his family friend Prithviraj Kapoor, who introduced him to director Debaki Bose, who offered him a debut role in his film Sunehra Sansar (1936).
Through the 1940s and 1950s, Singh appeared in several iconic movies of the era, including Sikandar (1941), Jwar Bhata (1944) (Dilip Kumar's film debut), Humayun (1945), Awara (1951), Jaal (1952), CID (1956), Howrah Bridge (1958), Chalti Ka Naam Gaadi (1958), Amrapali (1966) and An Evening in Paris (1967).
His suave style, baritone voice and menacing eyes became legendary – so much so that on one occasion (in his own words) "Even off-screen I was a bad man.
He died in Mumbai on 31 January 2000 aged 91 and was survived by his adopted son Pushkar, who is a producer of television serials.