PUBLISHED: 00:25, Wed, Sep 23, 2020 | UPDATED: 00:25, Wed, Sep 23, 2020
The North Korean vessel was located by South Korean authorities in December 2018. Dissidents on-board the ship had planned to assassinated Kim Jong-un, the former Japanese official warned.
At the time, the incident was not widely reported as other issues had dominated including events involving a South Korean warship and a Japanese patrol aircraft.
The former chief of the Japanese Self-Defence Forces’ Joint Chiefs of Staff, Admiral Katsutoshi Kawano, told the Japanese magazine Shukan Gendai about the assassination attempt.
He explained that the ship was carrying North Korean military officers who had tried to kill Mr Kim.
He added how South Korean authorities deployed a military destroyer ship after the North had issued emergency communication.
Kim Jong-un narrowly missed an assassination attempt according to a former official (Image: getty)
South Korean authorities deployed a military destroyer ship (Image: getty)
North Korea demanded that the boat was returned but the passengers were trying to retreat from the regime after failing to kill Mr Kim.
Mr Kawano said: "Attempts by the North Korean military to assassinate Chairman Kim Jong Un in the Wonsan-Kalma region had been unsuccessful.
“Four people escaped that day and were headed to Japan by sea.”
But the South Korean ship that was later deployed became the main focus of the dispute with Japan after a Japanese aircraft flew close to the warship.
Japan insisted that the South Korean ship had targeted the Japanese aircraft with a radar.
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North Korea demanded that the fleeing boat was returned (Image: