GIFU (Kyodo) An elderly couple were found dead Saturday in their home in Gifu City from what appeared to be another case of carbon monoxide poisoning caused by a gas-powered water heater, police said.

The couple had been using the water heater, made more than 10 years ago by Paloma Industries Ltd., without the attached extractor fan plugged in because the fan was broken, they said. Hot water was found running from it when their bodies were found.

A series of fatal carbon monoxide poisonings involving Paloma heaters have triggered multiple lawsuits recently.

Junzo Kida, 82, and his wife Tokiko, 80, were found dead at around 4:50 a.m. by their son's wife, who lives in a separate house on the same premises.

Kida was found collapsed near a washbasin, and his wife was lying on her back in bed in an adjacent room. Their daughter-in-law went to check on the house after hearing the water heater's motor running all night.