A man who was demolishing the house of a woman on trial for murder and attempted murder charges in connection with the 1998 curry poisoning in Wakayama, western Japan, died of unknown causes Saturday, police said.

The 62-year-old worker, whose name was withheld, collapsed while tearing down the two-story, wooden house formerly occupied by 38-year-old Masumi Hayashi. and her husband, Kenji. The worker was rushed to a nearby hospital but pronounced dead upon arrival, according to police, who are investigating the cause of his death.

The man and other workers had resumed work on the house following lunch in the afternoon when the man said he felt sick and went to rest in his car, which was parked nearby at the site of the curry poisoning, the police said.

When a colleague went to see him, the man was unconscious. His heart had stopped by the time the ambulance arrived, they said.

Hayashi's 180-sq.-meter house was gutted by a fire in February. Police believe it was arson because nobody was living there at the time.

Destruction of the house started Thursday. The work is being funded by fire insurance taken out on the house. Hayashi, a former insurance saleswoman, is accused of mixing arsenic in curry that was served at a community festival on July 25, 1998. The curry killed four people. and sickened 63 others.

Hayashi and her husband were arrested in October that year on suspicion of insurance fraud. She was later indicted in the poisoning case.