Taipei- A Taiwan woman, angry that her husband was unfaithful, killed him Friday in front of their 10-year-old grandson and then dismembered his body, police said.

Wu Ah-yin, 57, and her husband Chiang Tien-tsai, 55, were both pork sellers in Tucheng, near Taipei. The couple often quarrelled because Wu had a mistress and often stayed out late, Wang Jen-hong, spokesman for the Tucheng Police Bureau, told reporters.

The couple quarrelled again when Chiang came home drunk about 1 am Friday. After Chiang had gone to sleep, Wu stabbed him with a butcher's knife, killing him, and dismembered his corpse, Wang said.

Wu cut off her husband's head, hands, feet and genitals, and then sat in a chair waiting to be arrested by police.

The couple's 10-year-old grandson, who was living with the couple because his father had died, saw the murder and ran to his uncle's home to report the killing. The uncle called police who arrested Wu.

Wu's brother told reporters that his sister had been depressed since her younger son died and was angry because her husband had a mistress.

"They have been married for 40 years, but my brother-in-law was having an affair and did not look after the family, so her anger exploded, causing her to kill him," he said.