A man has been detained and indicted on charges of sending letters to local media threatening to blow up the plane that the widow of former South Korean President Kim Dae-jung planned to take on her recent visit to North Korea, prosecutors said Monday.

The 33-year-old, surnamed Park, is suspected of writing a one-page letter threatening to blow up the plane on either the departure or the return of Lee Hee-ho's trip to the North last month, the Seoul Central District Prosecutor's Office said, adding that Park has been put on trial on charges of violating the Aviation Safety Law and obstruction of duties.

In the letter pretending to be from a local anti-North Korean organization, Park allegedly said that Lee's visit is "a scheme aimed at again extending the life of the North Korean regime."

Police said the organization is not real and was made up by Park.

During the police investigation, Park admitted his crime, saying he wanted to stop Lee from visiting the North.

Lee, a symbolic figure for inter-Korean reconciliation due to her late husband's accomplishments, returned home on Aug. 8, after a four-day trip to promote reconciliation on the divided Korean Peninsula.

Kim Dae-jung, who died in 2009, was the architect of the "sunshine" policy that actively pushed for cross-border exchanges and reconciliation. He held the first inter-Korean summit with then North Korean leader Kim Jong-il in 2000. At that time, Lee accompanied her husband to Pyongyang. (Yonhap)