Kilukkam (1991)

Joji (played by Mohanlal) is a tourist guide who meets Nandini (Revathi) whom he mistakes to be a rich woman and hangs around with her. But it is later revealed that she is mentally retarded and he is forced to give her shelter. Nischal (Jagathy Sreekumar) who is Joji's friend finds that Nandini is a missing person and there is a huge reward to find her. He prompts Joji to hide her till the reward is increased, but later Nandini reveals that she is not mentally ill and she is an illegitimate child in search of her father (played by Thilakan).