The United States has disclosed that it investigated Kim Hyun-hee shortly after the bombing of a Korean Air flight in 1987 and concluded that Kim was a North Korean agent.

The U.S. State Department recently unveiled 57 confidential documents on the bombing of Korean Air Flight 858, which show that U.S. investigators interrogated Kim and reported their findings to Washington in February 1988. The conclusion of the report was that Kim was working for the North.

The documents reveal that Washington was concerned at the time of a possible South Korean retaliation for the bombing. But no retaliation attempts were made as then South Korean President Chun Doo-hwan took into consideration that Seoul was preparing to host the Olympic Games in 1988, and a presidential race was unfolding at the time of the bombing.

The documents were released amid persistent rumors within South Korea that the 1987 bombing was not perpetrated by the North and that Kim was not a North Korean agent.