North Korea's allegation last week that South Korea's intelligence service had plotted against the country's leader, Kim Jong-il, caused a sensation. Though met with derision in Seoul, the announcement, unprecedented for Pyongyang, ignited a wave of speculation about who or what was behind it.
On Thursday, the communist state's official media carried a message from the state security ministry announcing that it had apprehended a man surnamed Ri who was, it said, on a '... terrorist mission given by a South Korean puppet intelligence-gathering organisation to do harm to the safety of the top leader'.
The ministry said that Ri crossed the border - it was unspecified which border, but the North Korea-China border is far more porous than the inter-Korean demilitarised zone - early this year and met the representative of a South Korean spy agency, surnamed Hwang.
The organisation equipped Ri with 'speech and acoustic-sensing and pursuit devices for tracking the movement of the top leader - and even violent poison', the report said.
South Korea's National Intelligence Service denied any involvement in the alleged plot, but a South Korean campaigner for human rights in the North claimed to have known and co-operated with the man in question.
North Korea has been at loggerheads with South Korea since February, when conservative president Lee Myung-bak came to power in Seoul following a decade of liberal rule that had seen the enactment of a number of highly conciliatory policies towards North Korea.