The Army concealed evidence for three months indicating that a 23-year-old conscript was subjected to severe assaults by his comrades in barracks that eventually led to his death.
Amid mounting public criticism of top brass for mishandling the probe, the Defense Ministry on Monday promised to reinvestigate the tragedy.
According to documents the ministry submitted to the National Assembly on Monday, the conscript, identified by his surname Yoon, fell into a coma on April 6 after being assaulted by his comrades in barracks and died the following day.
On April 7, military police confirmed the assault had taken place and arrested four of the assailants and reported the case higher up the chain of command.
The military in a press briefing that afternoon mentioned the incident as a simple case of assault leading to death.
The military later obtained evidence that Yoon had been forced by his comrades to eat toothpaste and was systematically assaulted every night as senior officers stood by. But the military kept mum about the new revelations.
This led to charges that officers tried to keep the lid on the abuse to avoid yet more negative publicity.
KBS news broke the story on July 30, and the Military Human Rights Center held a press conference the following day revealing the details. The center is a civic group that was formed to monitor human rights abuses in the military and seek improvements.
It said it had been monitoring the case since the beginning of July.
Defense Minister Han Min-koo claimed in a hearing on Monday that he was not informed of the incident when he took office on June 30 and only found out about it through media reports.
The ministry now says it wants to charge the assailants with murder instead of assault leading to death. The Army is considering letting soldiers have their own cell phones so they can report abuse.
Han issued a public apology and stripped the head of Yoon's division of his rank and vowed to make him face a disciplinary committee, while ordering a reinvestigation of the case.
Yoon was posthumously promoted to corporal.