"The Black Lizard" a.k.a. (Hei Xi Yi) (1981)

(Synopsis): Two sisters are married to two classmates. Ting Peng (Wang Jung) and Hsiao Hsuan (Yueh Hua). Both wives give birth on the same day. Ting's wife has a son, and knowing Hsiao's contempt for girls, has her own son exchanged for her sister's baby girl. Hsiao's wife holds up the baby boy, exposing a birthmark identical to that of his real father Ting. Hsiao sees the similarity, and immediately suspects her of adultery with his classmate. He kills mother and child in a jealous rage and then arranges a series of devious frame-ups. Ting's wife has died in the meantime, and the whole twisted truth does not come to light until Hsiao attempts to bury Tzu-chu alive, not realising that she is in fact his own daughter. Lung intervenes, and Hsiao goes berserk and kills himself.