Police said they will book Interior Minister Lee Sang-min on suspicion of dereliction of duty and professional negligence resulting in death, over the deadly crowd surge in Itaewon, following a complaint filed by a union of fire department workers.

The independent investigation team set up by the National Police Agency announced Wednesday it is looking into the allegations against Interior Minister Lee Sang-min as a suspect in connection with the crowd crush, following a complaint filed against him by a unionized firefighters group on Monday.

“If a complaint is filed, the person becomes a suspect,” Kim Dong-wook, spokesperson for the investigation team said on Wednesday. “We are reviewing whether Lee holds the right to command the police over the situation (in Itaewon) based on the Government Organization Act and if he holds specific, direct responsibility regarding the incident based on the Framework Act On The Management Of Disasters And Safety."

The team has notified the Corruption Investigation Office for High-ranking Officials on the charges against Lee, based on the Act On The Establishment And Operation Of The Corruption Investigation Office For High-ranking Officials. The law requires police to notify the office of the suspicions when high ranking officials are booked.

The head of the CIO has to respond to the police on the opening of a direct investigation within the next 60 days. Before the response, Lee will be investigated by the independent investigation team.

Attention will turn to Lee's responsibilities related to the crisis.

The Framework Act On The Management Of Disasters And Safety states that the Interior Minister is in charge of the disaster and safety management of the nation.

Lee has been saying that he does not have the right to command or supervise the police. He claims that his only right is over appointing personnel of high ranking police officers, aided by the police bureau of the Interior Ministry.

Within the past few days, the investigation team has widened its scope of investigation to the Interior Ministry and the Seoul Metropolitan government, targeting those with safety management responsibilities.

The team has kicked off its investigation of the Interior Ministry, bringing in a ministry official in charge of disaster management to testify on Tuesday. It brought in another ministry official in charge of safety measures the day before.

The investigation into the Itaewon tragedy and the authorities’ response had been accused of targeting only low ranking officials from the police, fire department and district office, without looking into top government figures who are required to function as the control tower during a disaster.

The team explained that it had to look into the on-scene response of related authorities first to figure out the chain of command and the response systems in related administrations.

The team has also brought in an official from the Seoul Metropolitan Government who is in charge of safety management. Another official from the city government in charge of safety plans was found dead at his home last week.

As Yongsan-gu district office falls under the supervision of the city government, the Seoul Metropolitan Government also holds safety responsibilities over the tragedy.