A military official said the suspected Chinese intelligence officer asked the Navy officer, who was working at the Defense Security Command (DSC), to hand over confidential data regarding THAAD. However, the requested information was not actually delivered to the Chinese, the official said.
"Military prosecutors discovered this fact and included it in a court paper when they indicted the Navy officer," the official said, declining to be named.
The case involves a lieutenant-commander in the Navy who was indicted on July 10 for allegedly leaking third-class confidential information on naval destroyers to the Chinese officer in February.
On the day of the indictment, a high-ranking official of the military prosecution told reporters that the suspected Chinese agent asked the DSC officer, whose identity was withheld, to hand over information about the Korean Air and Missile Defense systems, but not THAAD.
At the time, there were media reports speculating that information about THAAD could have been handed over to Beijing.
THAAD is a core asset of the U.S. global multi-layered missile defense program, which Washington wants to deploy on the Korean Peninsula. China believes that the system could be used to nullify its military strike capabilities.
The revelation of the omission suggests the military might have deliberately lied about the case in consideration of its possible impact on Seoul-Beijing relations.
It is also seen as the military's apparent efforts to protect its own members.
As the controversy escalated, Ministry of National Defense spokesman Kim Min-seok said the omission was a "mistake." "It is regrettable that the military's briefing has caused misunderstandings to the public as well as reporters," he said in a regular briefing, Monday.
Kim said the military prosecution just tried to sum up the situation to make the briefing shorter when trying to explain the DSC officer had never handed over information about THAAD. He stressed that it was not a deliberate lie.
The military has been frequently embroiled in controversy for trying to hide key information during media briefings.
Last year, it was criticized for attempting to minimize the death of a private first class who died in April after he was tortured by colleagues.
In its first briefing, the military covered up the fact that the victim was severely beaten by saying that the cause of death was suffocation caused by an obstruction of his airway.