Prosecutors are seeking a 20-year prison sentence for the head of a battery manufacturer involved in a Hwaseong lithium battery plant fire that killed 23 people and injured eight others in 2023.

The prosecution requested such heavy punishment against Aricell chief Park Soon-kwan on Wednesday, on charges of violating the Serious Accidents Punishment Act, the Act on the Protection of Temporary Agency Workers and the Occupational Safety and Health Act.

The state agency also sought a 15-year prison term for Park Joong-eon, the company chief's son and head of factory management, on charges of violating the Occupational Safety and Health Act, as well as occupational and gross negligence causing death and injury.

Calling the accident the worst case of casualties since the Serious Accidents Punishment Act was enforced, prosecutors said the company chief abandoned and neglected workplace safety management, while only focusing on increasing productivity through low-wage labor by illegal migrants.

The agency also accused the son of failing to fulfill his duty as the manager of safety, and passing the buck.

The prosecution believes Aricell not only failed to take health and safety precautions, but illegally dispatched 320 untrained workers to the factory, leading to a fire that started with a faulty battery and spread rapidly.