Tokyo- Japan's Supreme Court on Tuesday upheld the death sentence of a woman convicted of killing four people and sickening dozens of others with arsenic in 1998.

Masumi Hayashi, 47, was convicted of murder for poisoning a curry stew served at a community festival in the western city of Wakayama in 1998. Four people died including a 10-year-old child and a 16-year-old girl, while 63 others still suffer from aftereffects of arsenic.

Although prosecutors failed to produce clear physical evidence, the district court found the circumstantial evidence was sufficient to show that Hayashi had the intent to kill, it said.

Hayashi received death a sentence in 2002 from the district court after pleading not guilty. The court hearing began in May 1999.

In 2005, the Osaka High Court upheld the lower court's ruling, and it also found Hayashi guilty of attempting to kill her husband and an acquaintance with arsenic for their insurance money.

Prosecutors argued that Hayashi was motivated by rage at being shunned by other housewives in the neighborhood. The case enthralled Japan, where mass murder is uncommon.

Her defence counsel expressed doubt to the Supreme Court on scientific analysis saying arsenic in the curry stew was identical to samples found at Hayashi's house and places associated with her.

The attorneys also rebutted testimony by a neighbour that Hayashi was watching the curry pot alone at the festival.

But the court upheld the sentence, saying the trial showed that Hayashi was the only one who had access to arsenic and was able to mix the poison in the curry.

Eleven women have been sentenced to death in postwar Japan, and six are still awaiting execution. (dpa)