Nil Gavani Kadhali (1969)

A gang of diamond smugglers led by a wily chief is assets by Babu, his niece Malathy meets the CID officer Shankar and hands over a packet at an Airport lounge to be handed over to her uncle. and her elder sister Radha meets the pal Seetharaman and falls in love with him. The two Pairs go through severed adventure and expose the villains.