The South Korean prosecution said Monday that it will expand the probe into the toxic humidifier disinfectant case targeting government ministries.

It also temporarily delayed the announcement of the final result of its five-month-long investigation into the disinfectant case involving four companies.

The Seoul Central District Prosecutors’ Office said Monday that it has started to summon and question ministry officials related to the case on how they managed and responded to the onset of the toxic humidifier disinfectant tragedy in 2011.

The investigation will mainly target officials from the Ministry of Environment, the Ministry of Health and Welfare, the Ministry of Trade, Industry and Energy, the Ministry of Food and Drug Safety and the Korea Centers for Disease Control and Prevention.

The prosecution last week summoned three officials from the Korea Agency for Technology and Standards to ask why they had not included humidifier disinfectants in the category of industrial products that should receive the ministry’s mandatory safety test. Two officials from the Ministry of Food and Drug Safety were also questioned as witnesses.

Prosecutors also added that it will specifically look into how the manufacturers and distributors of toxic humidifier disinfectants went through approvals by the related government institutions in the early 2000s.

The prosecution had pressed charges last month against some 20 people -- mostly officials from Oxy Reckitt Benckiser, Lotte Mart, Home Plus and Cefu -- from companies related to the incident.

The expanded probe into the government comes after the National Assembly endorsed last week a plan to conduct a parliamentary probe into the toxic humidifier disinfectant case.

The plan was unanimously adopted Wednesday at the Assembly’s plenary session, permitting a special panel to carry out its own investigation for 90 days and to discuss how to compensate victims. The Justice Ministry and the prosecution were excluded from the subject list as the rival parties remained deadlocked over whether to include them.

The prosecution earlier this year had stated it will not consider government institutions as the subject of investigation. They had said there was no legal basis to question whether the damages related to toxic humidifier disinfectant was due to the negligence of related ministries or officials who had conducted epidemiologic surveys of product safety.

According to damage reports collected by the Korea Environmental Industry and Technology Institute under the Environment Ministry as of June 2016, at least 698 victims have lost their lives and 3,698 suffered from health damages since 2011. But civic groups have been claiming that the total number of victims is well above 200,000, due to the delayed response and insufficient action by the government.

By Kim Da-sol (ddd@heraldcorp.com)