Sachaa Jhutha (1970)

Bhola is a young musician who arrives in Bombay to try to make a living as a music player to get money for his crippled twin sister, Belu, to find a suitor to marry her. Ranjit Kamar is a wealthy businessman who moonlights as a diamond thief and smuggler who is the dead splitting image of Bhola. Bhola and Ranjit paths cross at a costume party Bhola unknowingly crashes in which Ranjit and his mistress Rita persuade the unsuspecting and naive country-bumkin Bhola to impersonate Ranjit for social engagements while the real Ranjit settles for his criminal activities, while an undercover policewoman pursues Bhola/Ranjit hoping to catch him in his latest thief.