SEOUL, South Korea — Looking for answers after the deaths of scores of children and pregnant women from a mysterious lung ailment, a group of families in South Korea began to focus on a potential cause: a cleaner called Oxy.

In 2011, South Korean officials suggested that toxic chemicals in Oxy — used to sanitize humidifiers and sold by the British consumer goods maker Reckitt Benckiser — and similar products were responsible for the deaths. Ninety-five have been confirmed by the government, which is also reviewing hundreds of additional cases reported by families, who claim more than 460 fatalities. The government’s punishment for Reckitt Benckiser: a $45,000 fine for falsely advertising Oxy as safe for humans.

Five years later, simmering anger over the deaths has hit Reckitt Benckiser — and prompted widening hostility to white-collar crime that is directed at foreign and local companies alike.

South Korean prosecutors in May arrested three local Reckitt Benckiser employees and charged them with professional negligence resulting in deaths. When a Reckitt Benckiser executive publicly apologized, a relative of a victim jumped onstage and slapped him in the back of the neck.