The documents, found in the crisis management office at Cheong Wa Dae, included a daily journal from the office drafted April 16, 2014, when the passenger ferry sank in waters off the country's western coast, killing more than 300 people, according to Im Jong-seok, the presidential chief of staff.
Im said the daily log showed the first report of the accident was made to then-President Park Geun-hye at 9:30 a.m., instead of at 10 a.m., as earlier claimed by the ousted leader and her aides.
The Cheong Wa Dae official said the document was revised Oct. 23, 2014, to say the first report was made at 10 a.m.
"The reason they pushed back the time of the first report to the president by half an hour appears to have been an attempt to reduce the time between the first report and Park's first order, said to have been made at around 10:15 a.m.," Im told a press briefing. (Yonhap)